Abstract: Systems and methods for improving the performance of dilution refrigeration systems are described. Filters and traps employed in the helium circuit of a dilution refrigerator may be modified to improve performance. Some traps may be designed to harness cryocondensation as opposed to cryoadsorption. A cryocondensation trap employs a cryocondensation surface having a high thermal conductivity and a high specific heat with a binding energy that preferably matches at least one contaminant but does not match helium. Multiple traps may be coupled in series in the helium circuit, with each trap designed to trap a specific contaminant or set of contaminants. Both cryocondensation and cryoadsorption may be exploited among multiple traps.

Abstract: Systems and methods for improving the performance of dilution refrigeration systems are described. Filters and traps employed in the helium circuit of a dilution refrigerator may be modified to improve performance. Some traps may be designed to harness cryocondensation as opposed to cryoadsorption. A cryocondensation trap employs a cryocondensation surface having a high thermal conductivity and a high specific heat with a binding energy that preferably matches at least one contaminant but does not match helium. Multiple traps may be coupled in series in the helium circuit, with each trap designed to trap a specific contaminant or set of contaminants. Both cryocondensation and cryoadsorption may be exploited among multiple traps.

Abstract: Systems and devices for providing differential input/output communication with a superconducting device are described. Each differential I/O communication is electrically filtered using a respective tubular filter structure incorporating superconducting lumped element devices and high frequency dissipation by metal powder epoxy. A plurality of such tubular filter structures is arranged in a cryogenic, multi-tiered assembly further including structural/thermalization supports and a device sample holder assembly for securing a device sample, for example a superconducting quantum processor. The interface between the cryogenic tubular filter assembly and room temperature electronics is achieved using hermetically sealed vacuum feed-through structures designed to receive flexible printed circuit board cable.

Abstract: Systems and devices for providing differential input/output communication with a superconducting device are described. Each differential I/O communication is electrically filtered using a respective tubular filter structure incorporating superconducting lumped element devices and high frequency dissipation by metal powder epoxy. A plurality of such tubular filter structures is arranged in a cryogenic, multi-tiered assembly further including structural/thermalization supports and a device sample holder assembly for securing a device sample, for example a superconducting quantum processor. The interface between the cryogenic tubular filter assembly and room temperature electronics is achieved using hermetically sealed vacuum feed-through structures designed to receive flexible printed circuit board cable.

Abstract: Systems and methods for improving the performance of dilution refrigeration systems include cryocondensation traps employed in the helium circuit of a dilution refrigerator may be modified to improve performance. A cryocondensation trap employs a cryocondensation surface having at least one temperature that preferably matches the temperature at which at least one contaminant freezes into a solid form from a gaseous form. A single trap with at least one continuous cryocondensation surface formed in a generally helical or spiral-like fashion with each region having a different temperature may be employed to trap a specific contaminant or set of contaminants. A single trap with multiple cryocondensation surfaces where each surface has a different temperature may be alternatively employed for the same purpose. To provide a temperature gradient in the cryocondensation trap, at least one region of the cryocondensation trap may be thermally coupled to a cold surface and/or a transfer tube.

Abstract: Systems and methods for improving the performance of dilution refrigeration systems are described. Filters and traps employed in the helium circuit of a dilution refrigerator may be modified to improve performance. Some traps may be designed to harness cryocondensation as opposed to cryoadsorption. A cryocondensation trap employs a cryocondensation surface having a high thermal conductivity and a high specific heat with a binding energy that preferably matches at least one contaminant but does not match helium. Multiple traps may be coupled in series in the helium circuit, with each trap designed to trap a specific contaminant or set of contaminants. Both cryocondensation and cryoadsorption may be exploited among multiple traps.

Abstract: Adaptations and improvements to tubular metal powder filters include employing cross sectional geometries of any suitable shape, aligning the inner conductor off-axis, replacing the inner conductive wire with a conductive trace or a superconductive trace carried by a printed circuit board, combining multiple filters within a single common outer conductive housing, and employing meandering and other non-parallel signal paths. The various adaptations and improvements are designed to accommodate single-ended and differential signaling, as well as superconducting and non-superconducting applications.

Abstract: An I/O system and device for use with superconducting device provides multi-stage filtering using superconducting electrical pathways, while providing good thermal conductivity to maintain low temperature of the various components and allowing the easy mounting and dismounting of a device sample from a refrigerated environment. Filtering may include a lumped element filter assembly including multiple plates each carrying a number of lumped element filters. Filtering may include a metal powder filter assembly including multiple metal power filters formed in passages of a substantially non-magnetic portions. A device sample holder assembly secures a device sample, for example a superconducting quantum processor, and provides signals, ground and good thermal conduction.

Abstract: Magnetic shields and magnetic shielding systems are described. The excessive spatial demands of known mu-metal/cryoperm and superconducting shielding systems are reduced by a new multi-piece shield construction approach. A complete magnetic shielding system for use with superconducting-based computing systems, such as superconducting quantum computing systems, is also described. This complete system may include mu-metal/cryoperm shields and superconducting shields using either compensatory magnetic fields, expulsion by temperature gradients, or a combination of the two.

Abstract: Adaptations and improvements to tubular metal powder filters include employing non-circular cross sectional geometries, aligning the inner conductor off-axis, replacing the inner conductive wire with a conductive trace carried on a printed circuit board, combining multiple filters within a single common outer conductive housing, and employing meandering and other non-parallel signal paths. The various adaptations and improvements are designed to accommodate single-ended and differential signaling, as well as superconducting and non-superconducting applications.

Abstract: Systems and devices for providing differential input/output communication with a superconducting device are described. Each differential I/O communication is electrically filtered using a respective tubular filter structure incorporating superconducting lumped element devices and high frequency dissipation by metal powder epoxy. A plurality of such tubular filter structures is arranged in a cryogenic, multi-tiered assembly further including structural/thermalization supports and a device sample holder assembly for securing a device sample, for example a superconducting quantum processor. The interface between the cryogenic tubular filter assembly and room temperature electronics is achieved using hermetically sealed vacuum feed-through structures designed to receive flexible printed circuit board cable.

Abstract: An I/O system and device for use with superconducting device provides multi-stage filtering using superconducting electrical pathways, while providing good thermal conductivity to maintain low temperature of the various components and allowing the easy mounting and dismounting of a device sample from a refrigerated environment. Filtering may include a lumped element filter assembly including multiple plates each carrying a number of lumped element filters. Filtering may include a metal powder filter assembly including multiple metal power filters formed in passages of a substantially non-magnetic portions. A device sample holder assembly secures a device sample, for example a superconducting quantum processor, and provides signals, ground and good thermal conduction.

Abstract: Adaptations and improvements to tubular metal powder filters include employing a polyester binder or a binder formed of vacuum grease, employing metal powders of multiple different chemical compositions and/or spanning multiple different ranges of grain-size, replacing the outer conductive housing and metal powder components with a single structure formed of sintered metal powder, and texturing (such as rifling, threading, sanding, or scratching) an inner surface of the outer conductive housing. The various adaptations and improvements are designed to accommodate single-ended and differential signaling, as well as superconducting and non-superconducting applications.

Abstract: Adaptations and improvements to tubular metal powder filters include employing non-circular cross sectional geometries, aligning the inner conductor off-axis, replacing the inner conductive wire with a conductive trace carried on a printed circuit board, combining multiple filters within a single common outer conductive housing, and employing meandering and other non-parallel signal paths. The various adaptations and improvements are designed to accommodate single-ended and differential signaling, as well as superconducting and non-superconducting applications.

Abstract: Magnetic shields and magnetic shielding systems are described. The excessive spatial demands of known mu-metal/cryoperm and superconducting shielding systems are reduced by a new multi-piece shield construction approach. A complete magnetic shielding system for use with superconducting-based computing systems, such as superconducting quantum computing systems, is also described. This complete system may include mu-metal/cryoperm shields and superconducting shields using either compensatory magnetic fields, expulsion by temperature gradients, or a combination of the two.

Abstract: Cryogenic refrigeration employs a pulse tube cryo-cooler and a dilution refrigerator to provide very low temperature cooling, for example, to cool superconducting processors. Continuous cryogenic cycle refrigeration may be achieved using multiple adsorption pumps. Various improvements may include multiple distinct thermal-linking points, evaporation pots with cooling structures, and/or one or more gas-gap heat switches which may be integral to an adsorption pump. A reservoir volume may provide pressure relief when the system is warmed above cryogenic temperature, reducing the mass of the system. Additional heat exchangers and/or separate paths for condensation and evaporation may be provided. Multi-channel connectors may be used, and/or connectors formed of a regenerative material with a high specific heat capacity at cryogenic temperature. Flexible PCBs may provide thermal links to components that embody temperature gradients.

Abstract: Systems and devices for providing differential input/output communication with a superconducting device are described. Each differential I/O communication is electrically filtered using a respective tubular filter structure incorporating superconducting lumped element devices and high frequency dissipation by metal powder epoxy. A plurality of such tubular filter structures is arranged in a cryogenic, multi-tiered assembly further including structural/thermalization supports and a device sample holder assembly for securing a device sample, for example a superconducting quantum processor. The interface between the cryogenic tubular filter assembly and room temperature electronics is achieved using hermetically sealed vacuum feed-through structures designed to receive flexible printed circuit board cable.