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 a quantum device with modular quantum building blocks are provided. In one embodiment, a device is provided that comprises a substrate that is coupled with a plurality of qubit pockets, where at least one qubit pocket of the plurality of qubit pockets is coupled with a qubit. In one implementation, the device can further comprise a plurality of connectors coupled to the substrate and positioned around at least a portion of the substrate, where the plurality of connectors comprising a connecting element. In one or more implementations, the device can further comprise a plurality of transmission lines formed on the substrate and connect at least one connector of the plurality of connectors to at least one qubit pocket of the plurality of qubit pockets.

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: A quantum circuit includes a first qubit and a second qubit. A bus resonator transmission line is coupled between the first qubit and the second qubit. A readout bus is coupled to the first qubit. A switch is coupled to the bus resonator transmission line between the first qubit and the second qubit.

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: 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: A quantum circuit includes a first qubit and a second qubit. A bus resonator transmission line is coupled between the first qubit and the second qubit. A readout bus is coupled to the first qubit. A switch is coupled to the bus resonator transmission line between the first qubit and the second qubit.

Abstract: Techniques regarding determining and/or analyzing temperature distributions experienced by quantum computer devices during operation are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise a region component that can define a plurality of temperature regions from a quantum computing device layout. The computer executable component can also comprise a map component that can generate a map that characterizes a temperature distribution by determining at least one temperature achieved within the plurality of temperature regions during an operation of the quantum computing device layout.

Abstract: Devices and methods that can facilitate vertical dispersive readout of qubits of a lattice surface code architecture are provided. According to an embodiment, a device can comprise a first substrate that can have a first side and a second side that can be opposite the first side. The first substrate can comprise a read pad that can be located on the first side and a readout resonator that can be located on the second side. The device can further comprise a second substrate that can be connected to the first substrate. The second substrate can comprise a qubit. In some embodiments, the device can further comprise a recess that can be located on the first side of the first substrate. The recess can comprise the read pad.

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: 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, computer-implemented methods, and computer program products that can facilitate determining a state of a qubit are described. According to an embodiment, a system can comprise a memory that stores computer executable components and a processor that executes the computer executable components stored in the memory. The computer executable components can comprise a relation determining component that can determine relation of a status signal of a quantum computing device to a noise value of the quantum computing device. The system can further include an operation time estimator that can estimate an operation time for the quantum computing device based on the relation of the status signal to the noise value.

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: Devices, systems, methods, and computer-implemented methods to facilitate employing thermalizing materials in an enclosure for quantum computing devices are provided. According to an embodiment, a system can comprise a quantum computing device and an enclosure having the quantum computing device disposed within the enclosure. The system can further comprise a thermalizing material disposed within the enclosure, with the thermalizing material being adapted to thermally link a cryogenic device to the quantum computing device.

Abstract: A system includes a quantum processor includes a plurality of qubits. For each qubit, there is a circulator operative to receive a control signal and an output signal from the qubit. An isolator is coupled to an output of the circulator. A quantum-limited amplifier is coupled to an output of the isolator and configured to provide an output of the qubit. A multiplexor (MUX) is configured to frequency multiplex the outputs of at least two of the plurality of qubits as a single output of the quantum processor.

Abstract: A device includes a first substrate formed of a first material that exhibits a threshold level of thermal conductivity. The threshold level of thermal conductivity is achieved at a cryogenic temperature range in which a quantum circuit operates. In an embodiment, the device also includes a second substrate disposed in a recess of the first substrate, the second substrate formed of a second material that exhibits a second threshold level of thermal conductivity. The second threshold level of thermal conductivity is achieved at a cryogenic temperature range in which a quantum circuit operates. In an embodiment, at least one qubit is disposed on the second substrate. In an embodiment, the device also includes a transmission line configured to carry a microwave signal between the first substrate and the second substrate.

Abstract: The technology described herein is directed towards a cryogenic-stripline microwave attenuator. A first high thermal conductivity substrate such as sapphire and a second high thermal conductivity substrate such as sapphire, along with a signal conductor comprising one or more attenuator lines between the substrates form a stripline. A compression component such as one or more screws, vias (plus clamps) and/or clamps presses the first high thermal conductivity substrate against one side of the signal conductor and presses the second high thermal conductivity substrate against another side of the signal conductor. The high thermal conductivity of the substrates facilitates improved thermalization, while the pressing of the substrates against the conductor reduces the thermal boundary (Kapitza) resistance and thereby, for example, improves thermalization and reduces thermal noise.