Abstract: An electronic filtering device includes continuous trace on a dielectric substrate and a dissipation layer communicatively coupled to the trace. The dissipation layer may include disconnected metal particles, which may be embedded in a substrate, for example in an epoxy. The continuous trace may be meandering, for example crenulated, coil or spiral signal path. At least a second continuous trace may be spaced from the first by the substrate, and conductively coupled by a via. The electronic filtering device may be used in one or more printed circuit boards (PCBs) that form stages of an input/output system.

Abstract: An electronic filtering device includes continuous trace on a dielectric substrate and a dissipation layer communicatively coupled to the trace. The dissipation layer may include disconnected metal particles, which may be embedded in a substrate, for example in an epoxy. The continuous trace may be meandering, for example crenulated, coil or spiral signal path. At least a second continuous trace may be spaced from the first by the substrate, and conductively coupled by a via. The electronic filtering device may be used in one or more printed circuit boards (PCBs) that form stages of an input/output system.

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: Systems and methods for magnetic shielding are described. A magnetic shield formed of a material having a high magnetic permeability may be degaussed using a toroidal degaussing coil. The toroidal degaussing coil may enclose at least a portion of the shield. Magnetic field gradients may be actively compensated using multiple magnetic field sensors and local compensation coils. Trapped fluxons may be removed by an application of Lorentz force wherein an electrical current is passed through a superconducting plane.

Abstract: A localized area is at least partially contained within a perimeter of a shield ring formed by a closed superconducting current path of a material that is superconductive below a critical temperature. The shield ring is at least partially within a perimeter of a compensation coil that is coupled to a current source. One or more measurement devices are responsive to magnetic fields in the vicinity of the localized area, allowing compensation by controlling current to the compensation coil. A heater can raise temperature of the shield ring out of a superconducting condition.

Abstract: SQUIDs may detect local magnetic fields. SQUIDS of varying sizes, and hence sensitivities may detect different magnitudes of magnetic fields. SQUIDs may be oriented to detect magnetic fields in a variety of orientations, for example along an orthogonal reference frame of a chip or wafer. The SQUIDS may be formed or carried on the same chip or wafer as a superconducting processor (e.g., a superconducting quantum processor). Measurement of magnetic fields may permit compensation, for example allowing tuning of a compensation field via a compensation coil and/or a heater to warm select portions of a system. A SQIF may be implemented as a SQUID employing an unconventional grating structure. Successful fabrication of an operable SQIF may be facilitated by incorporating multiple Josephson junctions in series in each arm of the unconventional grating structure.

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.

Abstract: A localized area is at least partially contained within a perimeter of a shield ring formed by a closed superconducting current path of a material that is superconductive below a critical temperature. The shield ring is at least partially within a perimeter of a compensation coil that is coupled to a current source. One or more measurement devices are responsive to magnetic fields in the vicinity of the localized area, allowing compensation by controlling current to the compensation coil. A heater can raise temperature of the shield ring out of a superconducting condition.

Abstract: A device is at least partially contained within a shielded enclosure formed by a first material that has a high thermal conductivity and plated with a second material that is superconductive below a critical temperature. An exterior of the shielded enclosure is at least partially wound by a compensation coil that is coupled to a current source. One or more measurement devices are responsive to magnetic fields in close proximity to the device, allowing compensation by controlling current to the compensation coil. Thus, magnetic shielding may be provided by compensation fields that may be trapped within the shielded enclosure when the system is cooled below the critical temperature of the second material. Radiation shielding may be provided by cooling the shielded enclosure to a temperature that is approximately equal to the temperature of the device.

Abstract: An electronic filtering device includes continuous trace on a dielectric substrate and a dissipation layer communicatively coupled to the trace. The dissipation layer may include disconnected metal particles, which may be embedded in a substrate, for example in an epoxy. The continuous trace may be meandering, for example crenulated, coil or spiral signal path. At least a second continuous trace may be spaced from the first by the substrate, and conductively coupled by a via. The electronic filtering device may be used in one or more printed circuit boards (PCBs) that form stages of an input/output system.

Abstract: Superconducting connections are provided to internal layers of a multi-layer circuit board structure, for example by superconducting vias.