阅读说明：本技术 用于低温环境的降低的卡皮查阻抗微波滤波器 (Reduced impedance microwave filter for low temperature environments ) 是由 P·古曼 S·B·欧利瓦德瑟 于 2019-09-20 设计创作，主要内容包括：提供了用于热解耦设备的架构和用于制造热解耦设备的技术。在一些实施例中,热解耦设备可包括在热解耦低温微波滤波器中。在一些实施例中,热解耦设备可包括电介质材料和导线。电介质材料可包括通过电介质材料的壁与第二通道分离的第一通道。导线可包括由壁分离的第一片段及第二片段。壁可促使微波信号在第一片段与第二片段之间的传播,并且可减少导线的第一片段与第二片段之间的热流。(Architectures for thermal decoupling devices and techniques for fabricating thermal decoupling devices are provided. In some embodiments, the thermally decoupled apparatus may be included in a thermally decoupled low temperature microwave filter. In some embodiments, the thermally decoupled device may include a dielectric material and a conductive line. The dielectric material may include a first channel separated from a second channel by a wall of the dielectric material. The wire may include a first segment and a second segment separated by a wall. The wall may facilitate propagation of the microwave signal between the first and second segments and may reduce heat flow between the first and second segments of the wire.)

1. A thermally decoupled apparatus, comprising:

a dielectric material comprising a first channel separated from a second channel by a wall of the dielectric material; and

a wire comprising a first segment and a second segment separated by the wall, wherein the wall promotes propagation of microwave signals between the first segment and the second segment and reduces heat flow between the first segment and the second segment of the wire.

2. The thermally decoupled apparatus of claim 1, wherein the wall has dimensions determined for propagating the microwave signal based on the microwave signal having a frequency greater than about 1 gigahertz (GHz).

3. The decoupling apparatus of claim 1, wherein the first segment and the second segment extend in substantially parallel directions.

4. The thermally decoupled device of claim 1, wherein the first segment exhibits a first average temperature that is higher than a second average temperature of the second segment.

5. The thermally decoupled device of claim 1, wherein the dielectric material is selected to have a thermal conductivity greater than 200 watts per meter degree kelvin (W/m-K) at a temperature of 77 degrees kelvin (K).

6. The thermal decoupling apparatus of claim 5, wherein the dielectric material is selected from the group consisting of sapphire and diamond.

7. The thermally decoupled device of claim 1, wherein the conductive line comprises a conductive material that has been sintered in the discontinuous channel of dielectric material.

8. The apparatus of claim 1, wherein the dielectric material comprises a discontinuous channel comprising the first channel and the second channel, wherein the discontinuous channel is a pattern that facilitates a filtering operation on the microwave signal propagating in a low temperature environment having a temperature below about 77 degrees kelvin (K).

9. The decoupling apparatus of claim 8, wherein the filter operation is a function of a geometry of the conductive lines filling the discontinuous channels having the pattern.

10. The apparatus of claim 8, wherein the filtering operation comprises a band-pass filtering operation, wherein a first frequency of the microwave signal within a defined frequency range is passed by the band-pass filtering operation, and wherein a second frequency exceeding the defined range is attenuated by the band-pass filtering operation.

11. The thermally decoupled device of claim 10, wherein the defined frequency range has a bandwidth of approximately 1 gigahertz (GHz) that includes a portion of frequencies in a range between approximately 1GHz and approximately 10 GHz.

12. A thermally decoupled low temperature microwave filter apparatus comprising:

a dielectric having discontinuous channels in a pattern that facilitates filter operation on microwave signals propagating in a cryogenic environment having a temperature below about 77 degrees Kelvin (K), wherein the discontinuous channels comprise a first channel separated from a second channel by a wall of the dielectric; and

a wire including a first segment in the first channel and a second segment in the second channel, the first and second segments separated by the wall that promotes propagation of the microwave signal through the wire and reduces heat flow between the first and second segments of the wire.

13. The thermally decoupled cryogenic microwave filter apparatus of claim 12, wherein the wall has dimensions determined for propagating the microwave signal based on the microwave signal having a frequency above about 1 gigahertz (GHz).

14. A thermally decoupled cryogenic microwave filter device according to claim 12, wherein the first and second segments extend in substantially parallel directions.

15. The thermally decoupled cryogenic microwave filter apparatus of claim 12, further comprising a housing formed of a housing material and configured to be coupled to a refrigeration equipment board that facilitates transfer of thermal energy away from the housing, wherein the housing material is oxygen free or electrolytic copper.

16. The thermally decoupled cryogenic microwave filter apparatus of claim 15, wherein the housing is coupled to an electrical ground.

17. A method, comprising:

forming discontinuous channels in a dielectric by a fabrication apparatus, wherein the discontinuous channels have a pattern comprising first channels separated from second channels by walls of the dielectric; and

forming, by the manufacturing apparatus, a wire in the discontinuous channel of the dielectric material, wherein the wire comprises a first segment and a second segment separated by the wall that promotes propagation of a microwave signal between the first segment and the second segment and reduces heat flow between the first segment and the second segment of the wire.

18. The method of claim 17, wherein forming the conductive line comprises sintering a conductive material in the discontinuous channel.

19. The method of claim 18, wherein sintering the conductive material comprises:

depositing the conductive material in powder form in the discontinuous channel by the manufacturing apparatus; and

exposing, by the manufacturing apparatus, the conductive material in powder form to a sintering environment characterized by a defined temperature and a defined pressure selected to coalesce the conductive material in powder form onto the conductive wire without liquefying the conductive material.

20. The method of claim 19, wherein depositing the conductive material in powder form comprises depositing one of a group comprising: powdered gold, powdered copper, powdered silver, and powdered aluminum.

21. A method, comprising:

forming a dielectric from the manufacturing facility that operates as an electrical insulator and a thermal conductor at cryogenic temperatures below about 77 degrees kelvin (K), wherein the dielectric comprises a material having a thermal conductivity at 77K above about 200 watts per meter kelvin (W/m-K);

forming, by the fabrication apparatus, a discontinuous channel in the dielectric, wherein the discontinuous channel forms a pattern that facilitates a filtering operation on a microwave signal propagating in a low temperature environment, and the discontinuous channel comprises a first channel and a second channel separated by a wall of the dielectric; and

sintering, by the manufacturing apparatus, a conductive material in the discontinuous channel having the pattern, forming a wire comprising a first segment and a second segment separated by the wall, the first segment and the second segment promoting propagation of the microwave signal through the wire and reducing heat flow between the first segment and the second segment of the wire.

22. The method of claim 21, wherein forming the discontinuous channel comprises forming a first channel and a second channel separated by the wall, the wall having dimensions determined for propagating the microwave signal based on the microwave signal having a frequency greater than about 1 gigahertz (GHz).

23. The method of claim 21, wherein forming the discontinuous channel comprises forming a first channel and a second channel separated by the wall, wherein the first channel and the second channel are substantially parallel.

24. The method of claim 21, further comprising assembling a housing with the manufacturing apparatus, wherein the housing is configured to be coupled to a cold plate that facilitates transfer of thermal energy away from the housing.

25. A thermally decoupled product formed by a method comprising:

forming a first channel by a fabrication apparatus, the first channel separated from a second channel by a wall of dielectric material; and

forming a wire from the manufacturing apparatus, the wire including a first segment formed in the first channel and a second segment formed in the second channel and separated by the wall, wherein the wall allows microwave signals to propagate between the first and second segments and reduces heat flow between the first and second segments of the wire.

Technical field and background

The present invention relates generally to microwave filter components having segmented or discontinuous signal conductors that exhibit reduced kappa impedance (kapita resistance) in very low temperature environments.

Quantum computing is generally the use of quantum mechanical phenomena for the purpose of performing computational and information processing functions. Classical calculations, which typically operate on binary values using transistors, can be seen to differ from classical calculations. That is, while classical computers can work with bit values of 0 or 1, quantum computers can work with stacked qubits including 0 and 1, can tangle multiple qubits, and use interference.

Therefore, the basic element of quantum computation is a qubit (qubit). Qubits represent quantum mechanical systems in which information can be encoded and manipulated. An important aspect of a qubit is the coherence time, which represents how long the quantum state of the qubit can be maintained.

Successful implementation of quantum computing will likely exponentially expand the computational power of current computing systems, with the potential to revolutionize many areas of technology. Today, there are many proposed methods to implement quantum computing devices. One of the most feasible ways to implement quantum computing architectures is based on superconducting devices, which are typically implemented in cryogenic environments. The low temperature environment may be an environment having a very low pressure (e.g., vacuum or near vacuum) and a very low temperature. For example, in a superconducting-based quantum computing environment, for example, a cryogenic environment may exhibit temperatures below about 100 degrees kelvin (K) and may be as low as about 10 degrees kelvin (mK) or less.

The performance of any superconducting-based quantum computing architecture depends heavily on the quality of superconducting qubits (e.g., qubits), which can be directly characterized by measured coherence time and qubit error. These coherence times and qubit errors depend strongly on the performance of the microwave hardware (e.g., filter devices) at low temperatures.

While microwave filters do exist, even some are commercially declared suitable for cryogenic environments, existing microwave filters do not appear to be designed or tested to operate at temperatures below 77K, let alone temperatures that may accompany superconducting-based quantum computing implementations (e.g., near or below 10 mK).

Thus, a technical problem arises in the field of quantum computing, since at certain cryogenic temperatures (e.g., below about 77K), existing microwave frequency filters or attenuators can behave in an unexpected manner. For example, elements of a microwave filter or attenuator in a cryogenic environment may become superconducting and no longer serve to pass, filter, or attenuate signals based on frequency. The inventors have realized that these technical problems are at least partly due to two different technical problems.

A first technical problem arises due to the fact that signal conductors, such as coaxial cables or other hardware, span multiple temperature regions, typically spanning from a room temperature environment to a low temperature environment. Thus, the elements of the signal conductor (which may include wires to propagate the signal and a dielectric sheath or substrate) may have significant temperature differences. For example, a wire used to transmit a signal from a room temperature environment to a low temperature environment may vary in temperature by 300K. The inventors have recognized that significant temperature differences between different portions of a wire carrying a signal may cause thermal noise caused by heat flow or heat exchange between one portion of the wire and another portion of the wire. This thermal noise can degrade the performance of the microwave hardware, which in turn can degrade the qubit performance.

While the first technical problem relates to difficulties encountered due to heat flow within a single material (e.g., a wire), a second, different technical problem arises due to difficulties associated with heat flow between different materials. A second technical problem arises due to a phenomenon known as the kappa-check resistance, which tends to be negligible at room temperature or above low temperatures, but which can become very significant at low temperatures. The kappa-spected resistance refers to the thermal resistance effect at the boundary between different materials in the presence of heat flux. In other words, the impedance of the card reader may prevent various materials within the cryogenic environment from staying at a uniform temperature.

For example, assume that the ambient temperature and/or the temperature flux across the interface between two materials in a cryogenic refrigerator is 10 mK. Microwave hardware within the environment may include wires formed in a dielectric, where the wires may provide filtering, for example, by passing or attenuating frequency-based microwave signals. The dielectric can be cooled to 10 mK. However, wires that may represent a heat source in operation may not be able to effectively transfer heat from the wire to the dielectric due in part to the phenomenon of card impedance. Thus, the wires may be maintained at a temperature significantly higher than the ambient environment and/or the dielectric in which the conductive wires are located. The inventors have recognized that temperature differences between the dielectric and the wire can cause different problems, such as low frequency noise, unexpected behavior, and other problems, any of which can negatively impact the quality of qubits (e.g., coherence time and qubit errors) of quantum computing devices that rely on the microwave hardware.

A third technical problem is caused by the inability to thermalize the wire, which may be the source of heat in the system. A third technical problem may arise due to the various materials used to implement microwave hardware exhibiting insufficient thermal conductivity between two different materials (e.g., between a wire and a dielectric). Traditionally, dielectric and conductive materials have been selected based on electrical performance and cost, with little or no consideration of thermal performance.

Disclosure of Invention

The following presents a simplified summary in order to provide a basic understanding of one or more embodiments of the invention. This summary is not intended to identify key or critical elements or to delineate any scope of the particular embodiments or any scope of the claims. Its sole purpose is to present concepts in a simplified form as a prelude to the more detailed description that is presented later. In one or more embodiments described herein, systems, methods, apparatus, and/or products are described that facilitate at least one of reduced heat flow within a (failure) material or reduced impedance to skimming at a boundary between two different materials.

According to an embodiment of the present invention, a thermal decoupling apparatus may be provided. The thermal decoupling device may include a dielectric material. The dielectric material may include a first channel separated from a second channel by a wall of the dielectric material. The thermally decoupled device may further include a conductive wire. The wire may include a first segment and a second segment separated by a wall. The wall may facilitate propagation of the microwave signal between the first and second segments and may reduce heat flow between the first and second segments of the wire. An advantage provided by such a thermally decoupled device may be reduced thermal noise due to heat flow within the wire across multiple temperature zones. In some embodiments, the first and second channels may be arranged in a pattern (pattern) that facilitates filter operation on microwave signals propagating in a cryogenic environment having a temperature below about 77 degrees kelvin. An advantage of this arrangement is that the thermal decoupling device can be integrated into a filter device that provides a thermal decoupling filter device.

According to an embodiment of the present invention, a thermally decoupled low temperature microwave filter device may be provided. A thermally decoupled low temperature microwave filter apparatus may include a dielectric having discontinuous channels in a pattern that facilitates filter operation on microwave signals propagating in a low temperature environment having a temperature below about 77 degrees kelvin (K). The discontinuous channel may comprise a first channel separated from a second channel by a wall of dielectric. The thermally decoupled low temperature microwave filter apparatus may further include a wire. The wire may include a first segment located in the first channel and a second segment located in the second channel. The first segment and the second segment may be separated by a wall. The wall may facilitate propagation of the microwave signal between the first and second segments and may reduce heat flow between the first and second segments of the wire. The advantages provided by such thermally decoupled low temperature microwave filter devices may improve performance at very low temperatures, such as temperatures associated with low temperature environments in which quantum computing architectures may be implemented. For example, heat flow within the wires may cause thermal noise. This can be mitigated by thermally decoupling individual segments of the discontinuous wire. In some embodiments, the wall may have dimensions determined for propagating a microwave signal based on the microwave signal having a frequency greater than about 1 gigahertz (GHz). An advantage is provided in that even if the wire is discontinuous and therefore may not be suitable for dc applications, signals with sufficiently high frequencies may propagate between the discontinuous sections of the wire.

According to an embodiment of the present invention, a method may be provided. The method may be, for example, a method for implementing a thermal decoupling apparatus. The method may include forming a discontinuous channel in the dielectric by the fabrication device. The discontinuous channels may have a pattern including first channels separated from second channels by walls of dielectric material. The method may further comprise: the conductive lines are formed in discrete channels of dielectric material by a fabrication apparatus. The conductive line may include a first segment and a second segment. The first segment and the second segment may be separated by a wall that facilitates propagation of the microwave signal between the first segment and the second segment and reduces heat flow between the first segment and the second segment of the wire. An advantage provided by this approach may be reduced thermal noise due to heat flow within the wire across multiple temperature zones. In some embodiments, forming the conductive lines may include sintering (sinter) the conductive material in the discontinuous channels. An advantage provided by sintering the wire may be that the card inspection resistance between the wire and the substrate may be reduced due to the increased surface contact area between the wire and the substrate.

According to an embodiment of the present invention, a method may be provided. The method may be used, for example, for low temperature microwave filters that achieve thermal decoupling. The method can include forming a dielectric that operates as an electrical insulator and a thermal conductor at a cryogenic temperature of less than about 77 degrees kelvin (K) by fabricating the device. The dielectric may comprise a material having a thermal conductivity of greater than about 200 watts per meter kelvin (W/m-K) at 77K. The method may also include forming discontinuous channels in the dielectric by the fabrication equipment. The discontinuous channels may be formed in a pattern that facilitates filter operation on microwave signals propagating in a low temperature environment. The discontinuous channel may comprise a first channel and a second channel separated by a wall of dielectric. Still further, the method can include sintering the conductive material in the patterned discontinuous channels via the fabrication apparatus. This may result in a wire including a first segment and a second segment separated by a wall, which facilitates propagation of the microwave signal through the wire and reduces heat flow between the first segment and the second segment of the wire. An advantage provided by this approach may be reduced thermal noise along the wire. Another advantage may be reduced impedance between the wire and the dielectric. The reduction in thermal noise and the reduction in the impedance of the chipchecking may result in improved performance at very low temperatures (such as temperatures associated with low temperature environments in which quantum computing architectures may be implemented). For example, the impedance to the skimming can be reduced by increasing the surface contact area between the wire and the substrate. Sintering the wire may result in an increased surface contact area between the wire and the substrate.

According to one embodiment of the invention, a method of forming a thermally decoupled product can be provided. The method may include forming a first channel by a fabrication apparatus, the first channel separated from a second channel by a wall of dielectric material. The method may also include forming the wire by a manufacturing device. The wire may include a first segment formed in the first channel and a second segment formed in the second channel. The first segment and the second segment may be separated by a wall. The wall may allow the microwave signal to propagate between the first segment and the second segment and reduce heat flow between the first segment and the second segment of the wire. The advantages provided by this approach may result in a thermal decoupling product that may reduce heat flow between the various discrete segments of the wire via the discrete segments of the wire. Reducing heat flow may result in less thermal noise associated with the wires, which may provide an improved signal.

Drawings

FIG. 1 illustrates a diagram of a wire physically extending through multiple temperature environments in accordance with one or more embodiments.

FIG. 2 illustrates a block diagram of a thermally decoupled apparatus that can propagate a signal while reducing heat flow in accordance with one or more embodiments.

Fig. 3 illustrates a block diagram of a thermally decoupled cryogenic microwave filter apparatus that can propagate a signal while reducing heat flow in accordance with one or more embodiments.

FIG. 4 illustrates a block diagram of a system and an overlay temperature map showing the effect of Karman impedance in accordance with one or more embodiments.

FIG. 5 illustrates a block diagram of a cryogenic environment demonstrating the effect of the Karman impedance in accordance with one or more embodiments.

FIG. 6 shows a graphical depiction of an exemplary, non-limiting thermally decoupled cryogenic microwave filter with reduced Karman impedance in accordance with one or more embodiments.

Fig. 7 illustrates a block diagram of an example housing for a cryogenic microwave filter in accordance with one or more embodiments.

Fig. 8-10 illustrate methods by which a thermally decoupled product or a suitable thermally decoupled low temperature microwave filter product may be produced in accordance with one or more embodiments.

FIG. 11 illustrates a flow diagram of an example non-limiting method for implementing a thermally decoupled apparatus in accordance with one or more embodiments.

FIG. 12 illustrates a flow diagram of an example non-limiting method for implementing a thermally decoupled cryogenic microwave filter in accordance with one or more embodiments.

FIG. 13 illustrates a flow diagram of an example non-limiting method for sintering conductive material in accordance with one or more embodiments.

Fig. 14 illustrates a flow diagram of an example non-limiting method for implementing an enclosure for a cryogenic microwave filter in accordance with one or more embodiments.

FIG. 15 illustrates a block diagram of an example non-limiting operating environment in which one or more embodiments described herein can be implemented.

Detailed Description

The following detailed description is merely illustrative and is not intended to limit the embodiments and/or the application or uses of the embodiments. Furthermore, there is no intention to be bound by any expressed or implied information presented in the preceding background or summary or the detailed description.

As described above, the subject matter disclosed herein may solve various technical problems. For example, a first technical problem arises due to thermal noise caused by heat flow within a single material spanning multiple temperature zones, which is discussed primarily in conjunction with fig. 1-3 of the present disclosure. A second technical problem arises due to the impedance of the skimming operating at the interface between the two different materials, which is discussed primarily in connection with fig. 4-6 of the present disclosure.

Turning now to the drawings, and referring first to FIG. 1, a diagram of a wire 100 physically extending through multiple temperature environments is shown, in accordance with one or more embodiments. The wire 100 is shown as a continuous line or piece of wire that may be used to transmit signals between the cryogenic environment 102 and the laboratory environment 104. Portions of conductor 100 may be implemented as a coaxial cable or another suitable configuration. The wire 100 may be used in conjunction with superconducting quantum computing devices, which are typically implemented in a very low temperature environment 102.

The cryogenic environment 102 may be implemented inside a cryogenic refrigeration device that may have multiple stages, where each stage exhibits a different temperature. Thus, within the low temperature environment 102, there may be some positive integer number N of temperature zones. As shown, the core of the low temperature environment 102 representing temperature zone 0 may be very close to absolute zero, an example of which may be 10 millikelvin (mK). Other stages of the low temperature environment 102 may exhibit different temperatures ranging from about 10mK to about 100K. Beyond the low temperature environment 102, such as outside a cryogenic refrigeration device, the ambient temperature shown as temperature region R may be room temperature, which may approach 300K.

Thus, the conductor 100 for relaying signals between the core of the low temperature environment 102 and the laboratory environment 104 may operate not only as a current path but also as a thermal path. For example, the dc path typically relies on a continuous wire (e.g., wire 100), but a continuous wire is also an effective thermal path. As illustrated, heat will tend to flow into the wire 100 at regions in temperature region R and out of the wire 100 at regions in temperature regions 0 through N. In practice, heat will obviously tend to flow towards temperature zone 0.

The inventors have observed that such heat flow may cause thermal noise that may negatively affect the quality of signals transmitted by the conductor 100 or negatively affect devices served by the conductor 100. For example, the thermal noise may degrade the performance of the filter device or degrade the quality of the superconducting qubits of the quantum computing device. Thus, thermal noise represents a technical problem. Mitigating such thermal noise may improve the performance of filter devices, quantum computing devices, and other devices or systems. Techniques for reducing or mitigating thermal noise caused by heat flow within a wire can be found in connection with fig. 2.

Referring now to fig. 2, a block diagram of a thermal decoupling apparatus 200 that can propagate a signal while reducing heat flow is shown in accordance with one or more embodiments. Repeated descriptions of similar elements employed in other embodiments described herein are omitted for the sake of brevity. This may be achieved by dividing the wire into two or more discrete segments.

For example, the thermally decoupled device 200 can include a dielectric material 202, and depending on the implementation, the dielectric material 202 can be a sheath, a conduit, or a substrate. The dielectric material 202 may be any suitable material, but may be biased toward certain materials or characteristics, such as reduced impedance to skimming characteristics as further detailed in connection with fig. 6. The dielectric material 202 may include a first channel separated from a second channel by a wall 204 of the dielectric material 202. As described in detail below, the first and second channels may be filled or occupied by discrete segments of the wire 206. In some embodiments, the first channel and the second channel may extend in substantially parallel directions. By proxy, the first and second segments of the wire may extend in substantially parallel directions.

The walls 204 are depicted in dark gray to illustrate the spacing between the first and second channels, while the remainder of the dielectric material 202 is illustrated in light gray. In some embodiments, the walls 204 may be substantially the same as the dielectric material 202 or have substantially similar properties as the dielectric material 202. In some embodiments, the walls 204 may be composed of a different material having different properties than the dielectric material 202.

The thermally decoupled device 200 can further include a conductive wire 206. The conductor 206 may be discontinuous or segmented rather than a continuous conductor as used in other systems. For example, the conductive line 206 may include a first segment 206A and a second segment 206B, which may occupy a first channel and a second channel, respectively, of the dielectric material 202. Thus, the first segment 206A and the second segment 206B may be separated by the wall 204. The wall 204 may be configured to facilitate propagation of the signal 208 between the first segment 206A and the second segment 206B and reduce heat flow between the first segment 206A and the second segment 206B.

According to standard models, a signal (e.g., signal 208) may be propagated through a conductor (e.g., wire 206) via a flow of electrons. If these electrons are in a relatively low energy state, which is typical for Direct Current (DC) applications, the continuity of the conductor is relied upon to convey the signal 208. Thus, it can be readily observed that signal 208 may propagate through first segment 206A. Signal portion 208A depicts signal 208 propagating through first segment 206A. For DC-type applications, however, signal 208 may not be able to flow to second segment 206B due to a discontinuity in wire 206 caused by wall 204.

However, at high frequencies, such as frequencies within the microwave spectrum, signal 208 may cause electrons of wire 206 to be excited, thereby representing a higher energy state. In this higher energy state, electrons can jump from one conductor to another conductor that is close enough. In other words, the wall 204 effectively operates as a capacitor, and the signal 208 may pass from the first segment 206A to the second segment 206B, which is illustrated by the signal portion 208B. Once through the wall 204, the signal 208 may travel along the second segment 206B, which is illustrated by signal portion 208C.

The microwave spectrum is generally considered to be from about 300 megahertz (MHz) to about 300 gigahertz (GHz). Depending on various factors, including the size of the walls 204, the lower frequency may excite electrons sufficiently to cause the above-described effect. Thus, the signal 208 is not necessarily limited to frequencies at or above the microwave spectrum, but this is a suitable threshold for many technical applications.

For typical quantum computing applications or for low temperature frequency filters or other hardware, the signal 208 will typically have a frequency above about 1 GHz. Thus, in some embodiments, the wall 204 may have dimensions determined to propagate a signal 208 having a frequency greater than about 1 GHz. While many dimensions are suitable, as one example, the thickness of the wall 204 (e.g., the distance between the first segment 206A and the second segment 206B) may be about 0.6 millimeters. This thickness may allow signal 208 to propagate between first segment 206A and second segment 206B, but still reduce heat flow between first segment 206A and second segment 206B, which is illustrated by reference numeral 210. However, it should be understood that other dimensions may be suitable and may vary based on the embodiment. This is typically within a range defined by the maximum thickness that a given signal 208 can pass through the wall 204, which is heavily influenced by the frequency of the signal 208, and the minimum thickness still sufficiently reduces heat flow between the first and second segments 206A and 206B, which is heavily influenced by the material or thermal properties of the wall 204.

Recall that the wire 206 may extend through many different temperature zones, possibly ranging from about 300K to less than 1K. Thus, a majority of first segment 206A and second segment 206B may be in different temperature zones, which may result in the two segments having significantly different temperatures. However, heat flow within the conductive line 206 may be limited within a given segment, which may reduce thermal noise. In this example, the majority of the displayed portion of the first segment 206A is in temperature zone 1, while the entirety of the displayed portion of the second segment 206B is in temperature zone 0. As such, the first segment 206A may exhibit a first average temperature that is higher than a second average temperature of the second segment 206B. In some embodiments, the first segment 206A may be stably maintained at a different temperature than the second segment 206B, while the signal 208 may still propagate therebetween.

Indeed, the first segment 206A and the second segment 206B may be thermally decoupled by the thermal decoupling apparatus 200. Heat may flow freely within a given segment, but heat flow between two different segments may be reduced. As an advantage, thermal noise caused by such heat flow through the wires 206 may be significantly reduced given that the walls 204 may reduce the heat flow. As another advantage, operation of the associated cryogenic refrigeration device may be more efficient or more effective because the continuous flow path from the room temperature region to the core of the cryogenic environment has been removed by the split conductor 206.

Turning back to fig. 1, it can be appreciated that the thermal decoupling apparatus 200 can be advantageously implemented at a boundary between different temperature zones of the low temperature environment 102, such as at a boundary between different stages of an associated low temperature refrigeration plant. For example, consider one or more thermally decoupled devices 200 located at a boundary between temperature region N (e.g., 100K) and temperature region R (e.g., 300K). The first segment of wire 100 located in temperature region N need not be exposed to heat flow from the second segment of wire 100 located in temperature region R. In contrast, the first segment may find some thermal equilibrium at or near 100K, while the second segment may find some thermal equilibrium at or near 300K. However, the signal may still propagate between the first segment and the second segment. Another advantage of the thermal decoupling apparatus 200 may be used in conjunction with a filter apparatus, an example of which is described in detail with reference to fig. 3.

Turning now to fig. 3, a block diagram of a thermally decoupled cryogenic microwave filter apparatus 300 that can propagate a signal while reducing heat flow in accordance with one or more embodiments is shown. Repeated descriptions of similar elements employed in other embodiments described herein are omitted for the sake of brevity. For example, the thermally decoupled low temperature microwave filter apparatus 300 may include one or more thermal decoupling apparatuses 200.

In this regard, the thermally decoupled low temperature microwave filter apparatus 300 may include a dielectric 302. The dielectric 302 may have discontinuous channels in a pattern 306, the pattern 306 facilitating filter operation on microwave signals propagating in a low temperature environment having a temperature below about 77 degrees kelvin. The discontinuous channel may have a first channel separated from a second channel by a wall 308 of the dielectric 302, an example of which is depicted in fig. 2.

The thermally decoupled cryogenic microwave filter apparatus 300 may also include a wire 304 that may have a plurality of discontinuous segments. For example, the wire 304 may include a first segment 304A located in a first channel and a second segment 304B located in a second channel separated by a wall 308. The wall 308 may facilitate propagation of the microwave signal through the wire 304 (such as through multiple segments of the wire 304). The walls 308 may further reduce heat flow between the first segment 304A and the second segment 304B. Accordingly, the various segments of the wire 304 may be thermally decoupled, which may advantageously reduce or mitigate thermal noise. Techniques related to the effect of reducing the impedance of the skipper can now be described starting with fig. 4.

Reference is now made to fig. 4, which is a block diagram of a system 400 and an overlay temperature map illustrating the effect of the kayaking impedance in accordance with one or more embodiments. Repeated descriptions of similar elements employed in other embodiments described herein are omitted for the sake of brevity. The system 400 may include two different materials that share a boundary interface 402, where one material is in contact with the other material. Therefore, in this example, material a contacts material B at boundary interface 402. In this example, it is assumed that the materials, or the interface between the two materials, are subjected to a common temperature flux and/or ambient temperature for both, referred to as T0. Further assume that material a has an initial temperature T1, and material B has an initial temperature T2 that is lower than T1.

At room temperature, where the effect of the kappa-check impedance tends to be negligible, material a and material B will likely settle to a common temperature as heat flows from material a to material B through boundary interface 402. However, at cryogenic temperatures where the effect of the kaprier impedance may be much more significant, the thermal boundary impedance R causes a temperature drop Δ T at the boundary interface 402. In other words, the thermal boundary impedance prevents some heat exchange between material a and material B so that material a and material B do not settle to the same temperature.

It is believed that this temperature mismatch is due to scattering of energy carriers (such as phonons or electrons) at the boundary interface 402. The probability of an energy carrier scattering at the boundary interface 402 rather than transferring heat through the boundary is a function of the energy state of the materials on both sides of the boundary interface 402. At cryogenic temperatures, these energy states are lower, resulting in much higher scattering probability. It has been observed that at low temperatures (e.g., cryogenic temperatures), the chuckship resistance phenomenon (also referred to as thermal boundary resistance) results in a significant temperature drop Δ T at the boundary interface 402 that serves as a boundary between two different materials. It is further observed that this temperature drop Δ T may lead to the technical problem detailed further in connection with fig. 5.

Referring now to FIG. 5, a block diagram of a cryogenic environment 500 illustrating the effect of the Karman impedance is shown, in accordance with one or more embodiments. Repeated descriptions of similar elements employed in other embodiments described herein are omitted for the sake of brevity. The low temperature environment 500 may exhibit a very low pressure or be a vacuum. The low temperature environment 500 may be chilled to very low temperatures, such as less than about 77K, and may actually be below 4K, and in some cases 10 millikelvin or less. Within the low temperature environment 500 may be some portion of a quantum computing architecture 502.

The quantum computing architecture 502 may include different microwave hardware 504, such as microwave frequency filters or attenuators. For example, a microwave frequency filter may be employed to control superconducting qubits of the quantum computing architecture 502. The internal structure of the microwave frequency filter may comprise a wire located in a dielectric. Thus, the wires share different instances of the boundary interface 506 with the dielectric, which may be similar to that described in connection with materials a and B in fig. 1. Assuming that the temperature flux across the boundary interface 506 is T0, the wire is at T1, and the dielectric is at T2, the chipchecking impedance may cause the temperature across the boundary interface 506 to drop by Δ T. In other words, the wire is not thermalized and maintains a temperature Δ T higher than the dielectric. It has been observed that temperature differences between the wires and the dielectric can cause the microwave hardware 504 to behave unexpectedly. For example, the temperature difference may result in low frequency noise or other degraded performance of the microwave hardware 504. This may result in shorter coherence times, increased qubit errors, or other degraded performance of the quantum computing architecture 502. In some cases, elements (e.g., wires) of the microwave hardware 504 may become superconducting at very low temperatures, in which case the microwave hardware 504 may not function as intended.

A potential solution to the above-described technical problem caused by the chucky impedance at boundary interface 506 may be implemented by various techniques to reduce the chucky impedance at boundary interface 506. This reduction in thermal boundary impedance may result in lower Δ T values, which may avoid performance degradation of the microwave hardware 504 at very low temperatures.

Fig. 6 is a graphical depiction of an example non-limiting low temperature microwave filter 600 with reduced chiplock impedance in accordance with one or more embodiments. Repeated descriptions of similar elements employed in other embodiments described herein are omitted for the sake of brevity. In some embodiments, the low temperature microwave filter 600 may be used to control qubits of a superconducting quantum computing architecture.

The low temperature microwave filter 600 may include a substrate 602. The substrate 602 may be formed of a dielectric material determined to have desired thermal characteristics. For example, a material may be determined to have a thermal conductivity greater than about 200 watts per meter kelvin (W/m-K) at a temperature of 77 degrees kelvin (K). In some embodiments, the material may be a dielectric material that acts as an electrical insulator. It should be appreciated that materials for conventional substrates or dielectrics tend to be selected based on some function of price and required electrical characteristics (e.g., electrical insulation). Without identifying the increased importance of the chuckian impedance at cryogenic temperatures and the fact that chuckian impedance may cause technical problems with filter devices, filter designers have had no obvious reason to consider the thermal conductivity characteristics of a dielectric or substrate, particularly where a given thermal conductivity characteristic may increase the cost of the dielectric or substrate without providing improved electrical characteristics.

However, by selecting a material determined to have a high thermal conductivity (higher than 200W/m-K at 77K in this example), the elements (e.g., wires 604) in contact with the substrate 602 may be more efficiently thermalized, which may reduce thermal noise. For example, hot electrons may be more effectively removed from the conductive line 604. Since the DC signal does not propagate between the various segments of the conductor 604, noise associated with the DC signal may be reduced or eliminated. The result of reducing noise may improve the performance of the associated component or system. For example, when relying on a low temperature microwave filter 600 rather than an existing microwave filter, the associated quantum computing system may achieve improved coherence time and fewer qubit errors.

In some embodiments, the material selected for substrate 602 may be sapphire. In some embodiments, the material selected for substrate 602 may be diamond. Other materials are possible as long as they exhibit sufficient thermal conductivity. Both sapphire and diamond have extremely high thermal conductivity, even when compared to typical ceramic substrates such as alumina. For example, alumina with high thermal conductivity is known to have a thermal conductivity of 157W/m-K at 77K, but due to its low cost and low electrical conductivity, alumina is one of the most commonly selected materials for ceramic substrates and/or dielectrics. In contrast, other materials such as sapphire and diamond have significantly better thermal conductivity at low temperatures, which is shown in table I.

TABLE I

Although alumina is believed to have a high thermal conductivity relative to many other materials, depending on the application, this is generally not high enough. As shown in table I, sapphire and diamond exhibit thermal conductivities at 77K of approximately ten times (in the case of sapphire) or more than twenty times (in the case of diamond). At even lower temperatures, such as 4K, sapphire and diamond can exhibit thermal conductivities that are more than two orders of magnitude higher than alumina. Thus, at cryogenic temperatures, when the substrate is composed of, for example, sapphire or diamond, the boundary interface between the substrate and the different material can be expected to have a reduced impedance to chucking and a lower Δ T than when composed of a more common material, such as alumina.

The low temperature microwave filter 600 may also include a wire 604. The conductive line 604 may be formed in a recess or recesses of the substrate 602. Conductor 604 may facilitate filter operation for microwave signals propagating in a low temperature environment having a temperature below about 77K.

In some embodiments, the filter operation facilitated by the wire 604 may be a function of the geometry of the recess in the substrate 602. For example, since the conductive lines 604 may be formed in these recesses or the conductive lines 604 may fill some portion of the recesses, the pattern of the recesses may provide or facilitate a desired filtering operation. In this example, pattern 606 illustrates one example of a suitable geometric shape. In some embodiments, the filtering operation facilitated by pattern 606 may be a band-pass filter operation, wherein frequencies of the microwave signal that are within a defined range are passed by the band-pass filter operation, and other frequencies outside the defined range may be filtered or attenuated by the band-pass filter operation.

As one example, pattern 606 may cause frequencies between 5.5 gigahertz (GHz) and 6.5GHz to pass while filtering or attenuating frequencies beyond a band of allowed frequencies (e.g., frequencies below 5.5GHz or above 6.5 GHz). It should be appreciated that the defined frequency range passed may have a bandwidth of approximately one GHz or some other value, depending on the geometry of pattern 606. This defined band of pass frequencies having a width of 1GHz or other widths may be located substantially anywhere in the microwave spectrum, which is typically between about 300 megahertz (MHz) and 300 GHz. However, for certain applications used in conjunction with quantum computing architectures, filtering or attenuating frequencies in the range between about 1GHz and about 10GHz may be of greater importance. For example, a pass frequency in a defined range between about 4.5GHz to about 5.5GHz, between about 5.5GHz to about 6.5GHz, between about 6.5GHz to about 7.5GHz (while attenuating frequencies outside this range), etc. may represent a typical microwave filter.

As already discussed, the low temperature microwave filter 600 may have significant advantages over other filter devices, particularly with respect to reducing the impedance of the chipcard and improving thermalization. The inventors have identified that the kappa-check resistance can be reduced by increasing the surface contact area between the substrate 602 and the wire 604, a technique that will be described in detail below. The inventors have further recognized that improved thermalization may be achieved by selecting materials for the low temperature microwave filter 600 that have very high thermal conductivity, which may, for example, improve the efficiency of transferring hot electrons away from the lead 604. As described above, this may be related to the material selected for the substrate 602, where the selected material has a thermal conductivity greater than about 200 (or some other suitable value) W/m-K, with materials such as sapphire and diamond being used as representative examples. It should be further understood that the material of the wire 604 may also be selected for high thermal conductivity properties, some examples of which are given below.

In addition to improving thermalization of the conductive lines 604, for example, by increasing the thermal conductivity of the materials used in the low temperature microwave filter 600, the impedance of the kappa check may also be reduced. For example, considering again the boundary interface 506 of fig. 5, note that one or more similar boundary interfaces may exist between the substrate 602 and the wire 604. While the interface between two different materials may be represented as a smooth interface, on a microscopic scale, the two materials may not be flush across the entire interface, resulting in a reduced surface contact area between the two different materials at the boundary interface. This reduced surface contact area represents a technical problem, since it leads to a higher card interrogation resistance or a higher Δ T.

The inventors have observed that both Δ T and kappa-ping resistance can be reduced by increasing the surface contact area between the wires 604 and the substrate 602, and have further determined that this can be accomplished in different ways. For example, the wire 604 may be configured or formed such that the contact at the boundary interface is more flush. As another example, the pressure at the boundary interface may be increased, resulting in more surface contact area.

A technique that may be used to advantage with both techniques may be to sinter the wires 604. In other words, the wire 604 may comprise a conductive material that has been sintered in the recess of the substrate 602. Additional information about the sintering technique can be found with reference to fig. 10. However, it should be understood that by sintering the wire 604, the surface contact area at the boundary interface between the two materials may be increased, in part, by creating a better "fit" with the surface of the substrate 602 and by exhibiting increased pressure at the interface that tends to smooth out microscopic defects where contact may not otherwise exist.

As can be further observed from the pattern 606 representing the pattern of the conductor 604, different operations of the filter may be performed by measuring Radio Frequency (RF) signals. Because conductor 604 is discontinuous or segmented, DC measurements may not be fully supported. This is not necessarily a disadvantage, as qubits typically operate at high frequencies (e.g., above 1GHz), and DC measurements are not often used for such applications. Furthermore, blocking the DC signal may be beneficial in view of the DC signal may deliver low frequency noise that may negatively affect the qubit.

Referring now to fig. 7, an exemplary housing 700 for a cryogenic microwave filter 600 in accordance with one or more embodiments. Repeated descriptions of similar elements employed in other embodiments described herein are omitted for the sake of brevity. The housing 700 may enclose all or a portion of the other components of the low temperature microwave filter 600. The housing 700 may include a housing material 702, which may have various advantageous properties. For example, in some embodiments, the housing material 702 may be formed of an oxygen-free material. In some embodiments, the housing material 702 may be electrolytic copper or a similar material. In some embodiments, the housing material 702 may shield elements of a low temperature microwave filter (e.g., low temperature microwave filter 600) from microwave noise, which may provide further improved performance.

As shown by the channel 704, the housing 700 may be configured to couple to a cold plate or other cryogenic component that facilitates thermal energy transfer away from the housing 700 or operates as a heat sink. In some embodiments, the housing 700 may be coupled to an electrical ground, as indicated by reference numeral 706. Still further, the housing 700 may be integrated into a suitable quantum computing architecture, such as being incorporated into a quantum bit housing. The connector 708 may be a single pole or high density microwave connector such as SMP, SMA, Ardent, etc. In some embodiments, the connectors 708 or the low temperature microwave filter 600 on both ends of the housing 700 may have the same properties (e.g., positive or negative). This configuration may reduce the number of connections on the sub-bit control line, resulting in a reduced number of reflection points and thus improved performance.

Fig. 8-10 illustrate a method of producing a suitable decoupling product in accordance with one or more embodiments. Repeated descriptions of similar elements employed in other embodiments described herein are omitted for the sake of brevity. In some embodiments, the thermally decoupled product may represent the thermally decoupled device 200 of fig. 2. In some embodiments, the thermal decoupling product may represent a portion of the thermally decoupled low temperature microwave filter apparatus 300 or low temperature microwave filter 600. In fig. 8-10, the thermally decoupled product is shown in cross-sectional views depicted at various stages of the illustrated method.

In this regard, fig. 8 illustrates forming a dielectric 800, such as by a fabrication facility. The manufacturing device may be controlled by a computing element that includes a processor and a memory storing executable instructions that, when executed by the processor, cause performance of operations. Examples of processors and memory, as well as other suitable computer or computing-based elements, may be found with reference to fig. 15.

In some embodiments, dielectric material 800 may be a substrate such as substrate 602. For example, the dielectric material 800 may operate as an electrical insulator and a thermal conductor at cryogenic temperatures below about 77K. The dielectric material 800 may include a material having a thermal conductivity higher than about 200W/m-K at 77K. It is understood that the thermal conductivity selected to meet a particular application may depend on the application, and thus other thermal conductivity values may be selected depending on the application or embodiment. For example, for different applications, the material of the dielectric material 800 may be selected to have a thermal conductivity, e.g., greater than 1000W/m-K at a temperature of 77K, greater than 1000W/m-K at a temperature of 20K, greater than 20W/m-K at a temperature of 10K, and greater than 10W/m-K at a temperature of 4K, or any suitable value of thermal conductivity at any cryogenic temperature. Table I above shows that these examples differ in thermal conductivity values at different temperatures from commonly used dielectrics such as alumina. As discussed, selecting a material with a suitably high thermal conductivity can significantly reduce the chuckling resistance and significantly reduce the temperature drop at the boundary interface Δ Τ.

Fig. 9 illustrates forming a channel in dielectric material 800, for example, by a fabrication device, in accordance with one or more embodiments. Repeated descriptions of similar elements employed in other embodiments described herein are omitted for the sake of brevity. For example, the manufacturing apparatus may form the channel 900A and the channel 900B. Channel 900A may be separated from channel 900B by walls 902 of dielectric material 800. In some embodiments, the pattern of channels may be configured as a function of filter operation for electromagnetic radiation having frequencies within the microwave spectrum (e.g., between 300MHz and 300 GHz). A representative example of such a pattern that may provide such behavior (shown from a top view) may be pattern 606. Thus, in some embodiments, channels 900A and 900B may represent a cross-section of pattern 606, except that channels 900A and 900B are discontinuous and separated by walls 902. The channels 900A and 900B may be created by patterning and etching techniques or any other suitable technique.

Fig. 10 illustrates a conductive line 1000 formed in vias 900A and 900B in accordance with one or more embodiments. Repeated descriptions of similar elements employed in other embodiments described herein are omitted for the sake of brevity. For example, the manufacturing apparatus may form a wire including a first segment formed in channel 900A and a second segment formed in channel 900B. A first segment of wire 1000 may be separated from a second region, segment, by wall 902. The wall 902 may be configured to allow a microwave signal (or a signal with sufficiently excited electrons) to propagate between the first and second fragments. Further, the wall 902 may reduce heat flow between the first and second segments of the wire 1000.

In some embodiments, the wire 1000 may be formed of a sintered conductive material. For example, the conductive line 1000 may be produced by, for example, manufacturing the device sintering conductive material in the vias 900A and 900B. Further details regarding sintering can be found in connection with fig. 13.

It is understood that a different boundary interface 1002 may exist between the conductive line 1000 and the dielectric material 800. As already described, the dielectric material 800 may comprise a material selected to have a very high thermal conductivity. Also, an electrically conductive material having high thermal conductivity may be selected in conjunction with wire 1000. The use of a material having a high thermal conductivity may improve the thermalization of the wire, thereby improving the performance of the low temperature microwave filter product. Furthermore, by sintering the conductive material, the surface contact area may be increased at the boundary interface 1002, which may reduce the impedance of the kappa check and further improve performance in low temperature environments.

Fig. 11-14 illustrate different methods according to the disclosed subject matter. While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the disclosed subject matter is not limited by the order of acts, as some acts may occur in different orders and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology could alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all illustrated acts may be required to implement a given methodology in accordance with the disclosed subject matter. Additionally, it should be further appreciated that the methodologies disclosed hereinafter and throughout this specification are capable of being stored on an article of manufacture to facilitate transporting and transferring such methodologies to computers.

FIG. 11 shows a flowchart 1100 of an example non-limiting method for manufacturing a thermal decoupling device in accordance with one or more embodiments. Repeated descriptions of similar elements employed in other embodiments described herein are omitted for the sake of brevity. At reference numeral 1102, a fabrication apparatus can form discontinuous channels in a dielectric. The discontinuous channels may have a pattern including first channels separated from second channels by walls of dielectric material.

At reference numeral 1104, the fabrication equipment can form conductive lines in the discontinuous channels of dielectric material. The wire may include a first segment and a second segment separated by a wall. The wall may facilitate propagation of the microwave signal between the first and second segments of the wire and may reduce heat flow between the first and second segments of the wire. In some embodiments, forming the conductive lines may include sintering the conductive material in the discontinuous channels.

Fig. 12 shows a flow diagram 1200 of an example non-limiting method for manufacturing a thermally decoupled cryogenic microwave filter in accordance with one or more embodiments. Repeated descriptions of similar elements employed in other embodiments described herein are omitted for the sake of brevity. At reference numeral 1202, the fabrication facility can form a dielectric that operates as an electrical insulator and a thermal conductor at cryogenic temperatures below about 77K. In this regard, the dielectric may include a material having a thermal conductivity at 77K that is higher than about 200W/m-K. By selecting the material to have a thermal conductivity above a specified threshold (in this case above about 200W/m-K at 77K), the heat exchange between the wire and the dielectric can be improved, which can improve the performance of the low temperature microwave filter when operated in a very low temperature environment. Suitable examples of materials may include sapphire materials, diamond materials, or other materials.

At reference numeral 1204, a fabrication apparatus can form a discontinuous channel in a dielectric. The discontinuous channels may be formed in a pattern that facilitates filter operation of microwave signals propagating in a low temperature environment. The discontinuous channel may comprise a first channel and a second channel separated by a wall of dielectric. Generally, microwave signals are characterized by signals having frequencies in the range between about 300MHz and about 300 GHz. In some embodiments, the wall may have dimensions determined for propagating a microwave signal based on the microwave signal having a frequency greater than about 1 GHz.

At reference numeral 1206, the fabrication apparatus can form conductive lines in the discontinuous channels of dielectric material. The wire may include a first segment and a second segment separated by a wall. The wall may facilitate propagation of the microwave signal between the first and second segments and may reduce heat flow between the first and second segments of the wire. By reducing the heat flow between the first and second segments, thermal noise near the wire may be reduced, which may result in an improved signal.

As mentioned above, the wire may be used as a microwave filter, based on the geometry of the channel. In some embodiments, forming the conductive lines may include sintering the conductive material in the discontinuous channels. It should further be noted that by sintering the conductive material, the resulting sintered wire may have a reduced impedance to kappa interrogation at the boundary interface between the wire and the dielectric. This reduced chuckling resistance may be due in part to the increased surface contact area at the boundary interface caused by the sintering process.

FIG. 13 shows a flow diagram 1300 of an example non-limiting method for sintering a conductive material in accordance with one or more embodiments. Repeated descriptions of similar elements employed in other embodiments described herein are omitted for the sake of brevity. At reference numeral 1302, a fabrication apparatus can deposit a conductive material in powder form in a recess of a substrate. The electrically conductive material in powder form may be one selected for superior thermal conductivity properties, as detailed with respect to the material of the substrate, which may improve the performance of the filter at low temperatures by reducing the temperature drop at the boundary of the wire and the substrate. In some embodiments, the conductive material in powder form may be one of powdered gold, powdered copper, powdered silver, and powdered aluminum.

At reference numeral 1304, the manufacturing apparatus can expose the conductive material in powder form to a sintering environment or sintering conditions. The sintering environment or condition may be characterized by a defined temperature and a defined pressure selected to coalesce the conductive material in powder form to the wire without liquefying the conductive material. By employing a sintering technique in conjunction with the wire, a higher surface contact area between the dielectric and the wire can be achieved, which can operate to reduce the impedance of the kappa check at low temperatures and thus improve the performance of the low temperature microwave filter at low temperatures.

Turning now to fig. 14, a flow diagram 1400 illustrates an exemplary non-limiting method for manufacturing a housing for a cryogenic microwave filter in accordance with one or more embodiments. Repeated descriptions of similar elements employed in other embodiments described herein are omitted for the sake of brevity. At reference numeral 1402, a manufacturing apparatus can form or assemble a housing for a cryogenic microwave filter. The housing may be configured to be coupled to a refrigeration device board that operates as a heat sink.

At reference numeral 1404, a manufacturing apparatus can form or assemble a connector. The connector may be coupled to the wire at an opposite end of the low temperature microwave filter. In some embodiments, the connectors may share the same characteristic type. For example, the connectors at both ends of the filter may both be male connectors or may both be female connectors. One advantage that may be realized by such an arrangement may be that the number of connections on the sub-bit control line may be reduced, which may result in a reduced number of reflection points. In this way, cleaner microwave control pulses may be provided and the performance of the filter may be improved.

At reference numeral 1406, the manufacturing apparatus can form a housing of a housing material selected to improve thermalization and potentially shield the filter element from noise. In some embodiments, the shell material may be an oxygen-free material. In some embodiments, the housing material may be electrolytic copper.

It should be understood that the present invention may be a system, method, and/or article of manufacture formed by a specific process. Some technical applications of the present invention may be provided by a computer program product in any possible level of integration technical detail. The computer program product may include a computer-readable storage medium having computer-readable program instructions embodied therewith for causing a processor to implement various aspects of the present invention.

The computer readable storage medium may be a tangible device that can hold and store the instructions for use by the instruction execution device. The computer readable storage medium may be, for example, but not limited to, an electronic memory device, a magnetic memory device, an optical memory device, an electromagnetic memory device, a semiconductor memory device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a Static Random Access Memory (SRAM), a portable compact disc read-only memory (CD-ROM), a Digital Versatile Disc (DVD), a memory stick, a floppy disk, a mechanical coding device, such as punch cards or in-groove projection structures having instructions stored thereon, and any suitable combination of the foregoing. Computer-readable storage media as used herein is not to be construed as transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission medium (e.g., optical pulses through a fiber optic cable), or electrical signals transmitted through electrical wires.

The computer-readable program instructions described herein may be downloaded from a computer-readable storage medium to a respective computing/processing device, or to an external computer or external storage device via a network, such as the internet, a local area network, a wide area network, and/or a wireless network. The network may include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. The network adapter card or network interface in each computing/processing device receives computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in a computer-readable storage medium in the respective computing/processing device.

Computer program instructions for carrying out operations of the present invention may be assembly instructions, Instruction Set Architecture (ISA) instructions, machine related instructions, microcode, firmware instructions, state setting data, configuration data for an integrated circuit, or source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C + + or the like and procedural programming languages, such as the "C" programming language or similar programming languages. The computer-readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet service provider). In some embodiments, aspects of the present invention are implemented by personalizing an electronic circuit, such as a programmable logic circuit, a Field Programmable Gate Array (FPGA), or a Programmable Logic Array (PLA), with state information of computer-readable program instructions, which can execute the computer-readable program instructions.

Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer-readable program instructions.

These computer-readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer-readable program instructions may also be stored in a computer-readable storage medium that can direct a computer, programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer-readable medium storing the instructions comprises an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.

The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer, other programmable apparatus or other devices implement the functions/acts specified in the flowchart and/or block diagram block or blocks.

The flowchart and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

In connection with fig. 15, the systems and processes described below may be embodied within hardware, such as a single Integrated Circuit (IC) chip, multiple ICs, an Application Specific Integrated Circuit (ASIC), and so forth. Further, the order in which some or all of the process blocks appear in each process should not be considered limiting. Rather, it should be understood that some of the process blocks may be performed in a variety of orders, not all of which may be explicitly described herein.

With reference to FIG. 15, an example environment 1500 for implementing various aspects of the claimed subject matter includes a computer 1502. The computer 1502 includes a processing unit 1504, a system memory 1506, a codec 1535, and a system bus 1508. The system bus 1508 couples system components including, but not limited to, the system memory 1506 to the processing unit 1504. The processing unit 1504 can be any of various available processors. Dual microprocessors and other multiprocessor architectures also can be employed as the processing unit 1504.

The system bus 1508 can be any of several types of bus structure including the memory bus or memory controller, a peripheral bus or external bus, or a local bus using any of a variety of available bus architectures including, but not limited to, Industry Standard Architecture (ISA), micro-channel architecture (MSA), extended ISA (eisa), Intelligent Drive Electronics (IDE), VESA Local Bus (VLB), Peripheral Component Interconnect (PCI), card bus, Universal Serial Bus (USB), Advanced Graphics Port (AGP), personal computer memory card international association bus (PCMCIA), firewire (IEEE 1394), and Small Computer Systems Interface (SCSI).

In various embodiments, the system memory 1506 includes volatile memory 1510 and non-volatile memory 1512, which may employ one or more of the disclosed memory architectures. The basic input/output system (BIOS), containing the basic routines to transfer information between elements within the computer 1502, such as during start-up, is stored in nonvolatile memory 1512. In addition, according to this disclosure, the codec 1535 may include at least one of an encoder or a decoder, where the at least one of an encoder or a decoder may be comprised of hardware, software, or a combination of hardware and software. Although codec 1535 is depicted as a separate component, codec 1535 may be included within non-volatile memory 1512. By way of illustration, and not limitation, nonvolatile memory 1512 can include Read Only Memory (ROM), programmable ROM (prom), electrically programmable ROM (eprom), electrically erasable programmable ROM (eeprom), flash memory, 3D flash memory, or resistive memory such as Resistive Random Access Memory (RRAM). In at least some embodiments, the non-volatile memory 1512 can employ one or more of the disclosed memory devices. Further, non-volatile memory 1512 can be computer memory (e.g., physically integrated with computer 1502 or its motherboard) or removable memory. Examples of suitable removable memory with which the disclosed embodiments may be implemented may include Secure Digital (SD) cards, Compact Flash (CF) cards, Universal Serial Bus (USB) memory sticks, and the like. Volatile memory 1510 includes Random Access Memory (RAM), which acts as external cache memory, and one or more of the disclosed memory devices may also be employed in various embodiments. By way of illustration and not limitation, RAM is available in many forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), and Enhanced SDRAM (ESDRAM).

The computer 1502 may also include removable/non-removable, volatile/nonvolatile computer storage media. Fig. 15 illustrates, for example a disk storage 1514. Disk storage 1514 includes, but is not limited to, devices like a magnetic disk drive, Solid State Disk (SSD), flash memory card, or memory stick. In addition, disk storage 1514 can include storage media separately or in combination with other storage media including, but not limited to, an optical disk drive such as a compact disk ROM device (CD-ROM), CD recordable drive (CD-R drive), CD rewritable drive (CD-RW drive) or a digital versatile disk ROM drive (DVD-ROM). To facilitate connection of the disk storage 1514 to the system bus 1508, a removable or non-removable interface is typically used such as interface 1516. It should be appreciated that the storage device 1514 may store information relating to a user. Such information may be stored or provided to a server or application running on the user device. In one embodiment, the user may be notified (e.g., via the output device 1536) of the type of information stored to the disk storage 1514 or transmitted to the server or application. The user may be provided with an opportunity to opt-in or opt-out of collecting or sharing such information with the server or application (e.g., via input from input device 1528).

It is to be appreciated that fig. 15 describes software that acts as an intermediary between users and the basic computer resources described in suitable operating environment 1500. Such software includes an operating system 1518. Operating system 1518, which can be stored on disk storage 1514, acts to control and allocate resources of the computer system 1502. Applications 1520 take advantage of the management of resources by operating system 1518 through program modules 1524 and program data 1526 (such as boot/close transaction tables) stored either in system memory 1506 or on disk storage 1514. It is to be appreciated that the claimed subject matter can be implemented with various operating systems or combinations of operating systems.

A user enters commands or information into the computer 1502 through input device 1528. Input devices 1528 include, but are not limited to, a pointing device such as a mouse, trackball, stylus, touch pad, keyboard, microphone, joystick, game pad, satellite dish, scanner, TV tuner card, digital camera, digital video camera, web camera, and the like. These and other input devices connect to the processing unit 1504 through the system bus 1508 via interface port(s) 1530. Interface port(s) 1530 include, for example, a serial port, a parallel port, a game port, and a Universal Serial Bus (USB). The output device 1536 uses some of the same types of ports as the input device 1528. Thus, for example, a USB port may be used to provide input to computer 1502 and to output information from computer 1502 to an output device 1536. Output adapter 1534 is provided to illustrate that there are some output devices 1536 that require special adapters, such as monitors, speakers, and printers, among other output devices 1536. The output adapters 1534 include, by way of illustration and not limitation, video and sound cards that provide a means of connection between the output device 1536 and the system bus 1508. It should be noted that other devices or systems of devices provide both input and output capabilities such as remote computer 1538.

The computer 1502 may operate in a networked environment using logical connections to one or more remote computers, such as a remote computer 1538. The remote computer 1538 can be a personal computer, a server, a router, a network PC, a workstation, a microprocessor based appliance, a peer device, a smart phone, a tablet, or other network node, and typically includes many of the elements described relative to the computer 1502. For purposes of brevity, only a memory storage device 1540 is illustrated with remote computer(s) 1538. Remote computer(s) 1538 is logically connected to computer 1502 through a network interface 1542 and then via communication connection 1544. Network interface 1542 encompasses wire or wireless communication networks such as local-area networks (LAN) and wide-area networks (WAN) and cellular networks. LAN technologies include Fiber Distributed Data Interface (FDDI), Copper Distributed Data Interface (CDDI), ethernet, token ring, and the like. WAN technologies include, but are not limited to, point-to-point links, circuit switching networks like Integrated Services Digital Networks (ISDN) and variations thereon, packet switching networks, and Digital Subscriber Lines (DSL).

Communication connection(s) 1544 refers to the hardware/software employed to connect the network interface 1542 to the bus 1508. While communication connection 1544 is shown for illustrative clarity inside computer 1502, it can also be external to computer 1502. The hardware/software necessary for connection to the network interface 1542 includes, for exemplary purposes only, internal and external technologies such as, modems including regular telephone grade modems, cable modems and DSL modems, ISDN adapters, and wired and wireless ethernet cards, hubs, and routers.

While the subject matter has been described above in the general context of computer-executable instructions of a computer program product that runs on a computer and/or computers, those skilled in the art will recognize that the disclosure also can, or can be, implemented in combination with other program modules. Generally, program modules include routines, programs, components, data structures, etc. that perform particular tasks and/or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the computer-implemented methods of the invention may be practiced with other computer system configurations, including single-processor or multiprocessor computer systems, minicomputers, mainframe computers, as well as computers, hand-held computing devices (e.g., PDAs, telephones), microprocessor-based or programmable consumer or industrial electronics, and the like. The described aspects may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. However, some, if not all, aspects of the disclosure may be practiced on stand-alone computers. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.

As used in this application, the terms "component," "system," "platform," "interface," and the like may refer to and/or may include a computer-related entity or an entity associated with an operating machine having one or more specific functions. The entities disclosed herein may be hardware, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a server and the server can be a component. One or more components can reside within a process and/or thread of execution and a component may be localized on one computer and/or distributed between two or more computers. In another example, respective components can execute from different computer readable media having different data structures stored thereon. The components may communicate via local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network such as the internet with other systems via the signal). As another example, a component may be a device having a specific function provided by mechanical parts operated by an electrical or electronic circuit, which is operated by a software or firmware application executed by a processor. In this case, the processor may be internal or external to the apparatus and may execute at least a portion of a software or firmware application. As yet another example, a component may be an apparatus that provides specific functionality through electronic components without mechanical components, where the electronic components may include a processor or other embodiment of software or firmware for executing functions attributed, at least in part, to the electronic component. In an aspect, a component may emulate an electronic component via, for example, a virtual machine within a cloud computing system.

Furthermore, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise, or clear from context, "X employs a or B" is intended to mean any of the natural inclusive permutations. That is, if X employs A; x is B; or X employs both A and B, then "X employs A or B" is satisfied under any of the foregoing circumstances. In addition, the articles "a" and "an" as used in this specification and the drawings should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. As used herein, the terms "example" and/or "exemplary" are used to mean serving as an example, instance, or illustration and are not intended to be limiting. For the avoidance of doubt, the subject matter disclosed herein is not limited by such examples. Moreover, any aspect or design described herein as "exemplary" and/or "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects or designs, nor is it intended to exclude equivalent exemplary structures and techniques known to those of ordinary skill in the art.

As used in this specification, the term "processor" may refer to substantially any computing processing unit or device, including, but not limited to, a single-core processor; a single processor with software multi-threaded execution capability; a multi-core processor; a multi-core processor having software multi-thread execution capability; a multi-core processor having hardware multithreading; a parallel platform; and parallel platforms with distributed shared memory. Additionally, a processor may refer to an integrated circuit, an Application Specific Integrated Circuit (ASIC), a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), a Programmable Logic Controller (PLC), a Complex Programmable Logic Device (CPLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. Further, the processor may utilize nanoscale architectures such as, but not limited to, molecular and quantum dot based transistors, switches, and gates, in order to optimize space usage or enhance performance of the user device. A processor may also be implemented as a combination of computing processing units. In this disclosure, terms such as "store", "data store", "database", and substantially any other information storage component related to the operation and function of the component are used to refer to "memory components", entities embodied in "memory", or components including memory. It will be appreciated that the memory and/or memory components described herein can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. By way of illustration, and not limitation, nonvolatile memory can include Read Only Memory (ROM), programmable ROM (prom), electrically programmable ROM (eprom), electrically erasable ROM (eeprom), flash memory, or nonvolatile Random Access Memory (RAM) (e.g., ferroelectric RAM (feram)). Volatile memory can include RAM, which can act as external cache memory, for example. By way of illustration and not limitation, RAM is available in many forms, such as Synchronous RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), Direct Rambus RAM (DRRAM), Direct Rambus Dynamic RAM (DRDRAM), and Rambus Dynamic RAM (RDRAM). Additionally, the memory components of systems or computer-implemented methods disclosed herein are intended to comprise, without being limited to, including these and any other suitable types of memory.

The foregoing includes only examples of system and computer-implemented methods. It is, of course, not possible to describe every conceivable combination of components or computer-implemented methods for purposes of describing the present disclosure, but one of ordinary skill in the art may recognize that many further combinations and permutations of the present disclosure are possible. Furthermore, to the extent that the terms "includes," "has," "having," and the like are used in the specification, claims, attachments, and drawings, such terms are intended to be inclusive in a manner similar to the term "comprising" as "comprising" is interpreted when employed as a transitional word in a claim. The description of the different embodiments has been presented for purposes of illustration but is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope of the illustrated embodiments. The terms used herein were chosen in order to best explain the principles of the embodiments, the practical application, or technical improvements to the techniques in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.