Abstract: A thermalization structure is formed using a cover configured with a set of pillars, the cover being a part of a cryogenic enclosure of a low temperature device (LTD). A chip including the LTD is configured with a set of cavities, a cavity in the set of cavities having a cavity profile. A pillar from the set of pillars and corresponding to the cavity has a pillar profile such that the pillar profile causes the pillar to couple with the cavity of the cavity profile within a gap tolerance to thermally couple the chip to the cover for heat dissipation in a cryogenic operation of the chip.

Abstract: A quantum mechanical circuit includes a substrate; a first electrical conductor and a second electrical conductor provided on the substrate and spaced apart to provide a gap therebetween; and a third electrical conductor to electrically connect the first electrical conductor and the second electrical conductor. The third electrical conductor is a poor thermal conductor.

Abstract: An architecture for, and techniques for fabricating, a thermal decoupling device are provided. In some embodiments, thermal decoupling device can be included in a thermally decoupled cryogenic microwave filter. In some embodiments, the thermal decoupling device can comprise a dielectric material and a conductive line. The dielectric material can comprise a first channel that is separated from a second channel by a wall of the dielectric material. The conductive line can comprise a first segment and a second segment that are separated by the wall. The wall can facilitate propagation of a microwave signal between the first segment and the second segment and can reduce heat flow between the first segment and the second segment of the conductive line.

Abstract: Techniques facilitating transfer port systems for cryogenic environments are provided. In one example, an outer vacuum chamber of a cryostat can comprise a sidewall encompassing an inner chamber comprising a sample mounting surface. The sidewall can comprise a feedthrough port providing access to the sample mounting surface from a region external to the outer vacuum chamber.

Abstract: Systems and techniques that facilitate scalable thermal energy recycling for cryogenic systems are provided. In various embodiments, a system can comprise at least one cryostat. In various aspects, the system can further comprise a thermal battery coupled to the at least one cryostat by a thermal exchange system. In various instances, the thermal battery can be configured to store thermal energy extracted from the at least one cryostat or to supply thermal energy to the at least one cryostat.

Abstract: A gated Josephson junction includes a substrate and a vertical Josephson junction formed on the substrate and extending substantially normal the substrate. The vertical Josephson junction includes a first superconducting layer, a semiconducting layer, and a second superconducting layer. The first superconducting layer, the semiconducting layer, and the second superconducting layer form a stack that is substantially perpendicular to the substrate. The gated Josephson junction includes a gate dielectric layer in contact with the first superconducting layer, the semiconducting layer, and the second superconducting layer at opposing side surfaces of the vertical Josephson junction, and a gate electrically conducting layer in contact with the gate dielectric layer. The gate electrically conducting layer is separated from the vertical Josephson junction by the gate dielectric layer.

Abstract: A qubit control system for a quantum computer includes an optical waveguide configured to receive and transmit therethrough a wavelength division multiplexed optical signal which has a plurality of modulated optical carriers, each optical carrier being at a different optical wavelength and carrying a digital qubit control signal; an optical demultiplexer optically coupled to the optical waveguide to receive the multiplexed optical signal to recover the plurality of modulated optical carriers; a plurality of photodetectors in communication with the optical demultiplexer; a plurality of cryogenic filters in communication with the plurality of photodetectors, each being configured to filter corresponding one of the plurality of digital qubit control signals to provide a corresponding one of a plurality of analog qubit control signals which is directed to a corresponding superconducting qubit and the photodetectors. The cryogenic filters are provided at a cryogenic temperature.

Abstract: A quantum computing system includes a dilution refrigerator having a plurality of chambers. A trapped ion computing device includes a first set of qubits in a given chamber of the plurality of chambers of the dilution refrigerator. A superconducting computing device having a second set of superconducting qubits is inside the given chamber of the plurality of chambers of the dilution refrigerator.

Abstract: An architecture for, and techniques for fabricating, a thermal decoupling device are provided. In some embodiments, thermal decoupling device can be included in a thermally decoupled cryogenic microwave filter. In some embodiments, the thermal decoupling device can comprise a dielectric material and a conductive line. The dielectric material can comprise a first channel that is separated from a second channel by a wall of the dielectric material. The conductive line can comprise a first segment and a second segment that are separated by the wall. The wall can facilitate propagation of a microwave signal between the first segment and the second segment and can reduce heat flow between the first segment and the second segment of the conductive line.

Abstract: Systems and/or methods provided herein relate to cooling of a component within a chamber of a cryostat. A system can comprise a cryostat having a cooling plate disposed within the cryostat, and a cooling feed line extending into the cryostat from external to the cryostat, which cooling feed line is thermally coupled to the cooling plate by a heat exchanger. In one or more embodiments, the system further can comprise a bulk cooling system that employs a liquifiable gas to provide cooling, wherein the bulk cooling system is fluidly coupled to the cooling feed line. In one or more embodiments, the system further can comprise a vacuum pump disposed at the cooling return line and external to the cryostat and physically decoupled from the cryostat by a section of the cooling return line disposed between the cryostat and the vacuum pump.

Abstract: Techniques facilitating low thermal conductivity support systems within cryogenic environments are provided. In one example, a cryostat can comprise a support rod and a washer. The support rod can couple first and second thermal stages of the cryostat. The washer can intervene between the support rod and the first thermal stage. The washer can thermally isolate the support rod and the first thermal stage.

Abstract: Devices, systems, methods, computer-implemented methods, apparatus, and/or computer program products that can facilitate a suspended Majorana fermion device comprising an ion implant defined nanorod in a semiconducting device are provided. According to an embodiment, a quantum computing device can comprise a Majorana fermion device coupled to an ion implanted region. The quantum computing device can further comprise an encapsulation film coupled to the ion implanted region and a substrate layer. The encapsulation film suspends the Majorana fermion device in the quantum computing device.

Abstract: Techniques facilitating increased operational reliability for jib cranes are provided. In one example, a jib crane can comprise a mast, a shaft mechanism, and a rod. The mast can extend vertically from a base structure. The shaft mechanism can be disposed within the mast. The rod can be coupled to a boom arm and can be disposed within the shaft mechanism. Rotation of the rod can facilitate continuous rotation of the boom arm about a longitudinal axis of the rod with respect to the base structure.

Abstract: A quantum computer includes a refrigeration system under vacuum including a containment vessel, a qubit chip contained within a refrigerated vacuum environment defined by the containment vessel. The quantum computer further includes a plurality of interior electromagnetic waveguides and a plurality of exterior electromagnetic waveguides. The quantum computer further includes a hermetic connector assembly operatively connecting the interior electromagnetic waveguides to the exterior electromagnetic waveguides while maintaining the refrigerated vacuum environment. The hermetic connector assembly includes an exterior multi-waveguide connector, an interior multi-waveguide connector, and a dielectric plate arranged between and hermetically sealed with the exterior multi-waveguide connector and the interior multi-waveguide connector. The dielectric plate permits electromagnetic energy when carried by the interior and exterior pluralities of electromagnetic waveguides to pass therethrough.

Abstract: Techniques for designing and fabricating quantum circuitry, including a coplanar waveguide (CPW), for quantum applications are presented. With regard to a CPW, a central conductor and two return conductor lines can be formed on a dielectric substrate, with one return conductor line on each side of the central conductor and separated from it by a space. The central conductor can have bridge portions that can be raised a desired distance above the substrate and base conductor portions situated between the bridge portions and in contact with the surface of the substrate; and/or portions of the substrate underneath the bridge portions of the central conductor can be removed such that the bridge portions, whether raised or unraised, can be the desired distance above the surface of the remaining substrate, and the base conductor portions can be in contact with other portions of the surface of the substrate that were not removed.

Abstract: Techniques regarding determining the temperature of one or more quantum computing devices are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a temperature component that can determine a temperature of a superconducting resonator based on a frequency shift exhibited by the superconducting resonator due to a change in kinetic inductance with a change in temperature.

Abstract: A system for transmission of quantum information for quantum error correction includes an ancilla qubit chip including a plurality of ancilla qubits, and a data qubit chip spaced apart from the ancilla qubit chip, the data qubit chip including a plurality of data qubits. The system includes an interposer coupled to the ancilla qubit chip and the data qubit chip, the interposer including a dielectric material and a plurality of superconducting structures formed in the dielectric material. The superconducting structures enable transmission of quantum information between the plurality of data qubits on the data qubit chip and the plurality of ancilla qubits on the ancilla qubit chip via virtual photons for quantum error correction.

Abstract: Techniques for facilitating reduced thermal resistance attenuator on high-thermal conductivity substrates for quantum applications are provided. A device can comprise a substrate that provides a thermal conductivity level that is more than a defined thermal conductivity level. The device can also comprise one or more grooved transmission lines formed in the substrate. The one or more grooved transmission lines can comprise a powder substance. Further, the device can comprise one or more copper heat sinks formed in the substrate. The one or more copper heat sinks can provide a ground connection. Further, the one or more copper heat sinks can be formed adjacent to the one or more grooved transmission lines.

Abstract: Techniques facilitating multiple cryogenic systems sectioned within a common vacuum space are provided. In one example, a cryostat can comprise a plurality of thermal stages and a thermal switch. The plurality of thermal stages can intervene between a 4-Kelvin (K) stage and a Cold Plate stage. The plurality of thermal stages can include a Still stage and an intermediate thermal stage that can be directly coupled mechanically to the Still stage via a support rod. The thermal switch can be coupled to the intermediate thermal stage and an adjacent thermal stage. The thermal switch can facilitate modifying a thermal profile of the cryostat by providing a switchable thermal path between the intermediate thermal stage and the adjacent thermal stage.

Abstract: Techniques facilitating efficient thermal profile management within cryogenic environments are provided. In one example, a cryostat can comprise a plurality of thermal stages intervening between a 4-Kelvin (K) stage and a Cold Plate stage. The plurality of thermal stages can include a Still stage and an intermediate thermal stage that provides additional cooling capacity for the cryostat. The intermediate thermal stage can be directly coupled mechanically to the Still stage via a support rod.