Abstract: A signal generating system is provided. The signal generating system provides a microwave signal to a plurality of qubits. The signal generating system includes a generator, an oscillator, a mixer, and a splitter. The oscillator generates an oscillator signal including a constant frequency. The generator generates a generator signal including an initial frequency. The mixer is electrically coupled to the generator and the oscillator. The mixer combines the generator and oscillator signals to produce the microwave signal. The splitter is electrically coupled to the mixer. The splitter fans-out the microwave signal to a plurality of physical lines. Each of the plurality of physical lines is electrically connected to a corresponding one of the plurality of qubits.

Abstract: Symmetrical qubits with reduced far-field radiation are provided. In one example, a qubit device includes a first group of superconducting capacitor pads positioned about a defined location of the qubit device, wherein the first group of superconducting capacitor pads comprise two or more superconducting capacitor pads having a first polarity, and a second group of superconducting capacitor pads positioned about the defined location of the qubit device in an alternating arrangement with the first group of superconducting capacitor pads, wherein the second group of superconducting capacitor pads comprise two or more superconducting capacitor pads having a second polarity that is opposite the first polarity.

Abstract: Symmetrical qubits with reduced far-field radiation are provided. In one example, a qubit device includes a first group of superconducting capacitor pads positioned about a defined location of the qubit device, wherein the first group of superconducting capacitor pads comprise two or more superconducting capacitor pads having a first polarity, and a second group of superconducting capacitor pads positioned about the defined location of the qubit device in an alternating arrangement with the first group of superconducting capacitor pads, wherein the second group of superconducting capacitor pads comprise two or more superconducting capacitor pads having a second polarity that is opposite the first polarity.

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.

Abstract: A signal generating system is provided. The signal generating system provides a microwave signal to a plurality of qubits. The signal generating system includes a generator, an oscillator, a mixer, and a splitter. The oscillator generates an oscillator signal including a constant frequency. The generator generates a generator signal including an initial frequency. The mixer is electrically coupled to the generator and the oscillator. The mixer combines the generator and oscillator signals to produce the microwave signal. The splitter is electrically coupled to the mixer. The splitter fans-out the microwave signal to a plurality of physical lines. Each of the plurality of physical lines is electrically connected to a corresponding one of the plurality of qubits.

Abstract: The technology described herein is directed towards microwave attenuators, and more particularly to a cryogenic microwave attenuator device for quantum technologies. In some embodiments, a device can comprise a cryogenic microwave attenuator device. The cryogenic microwave attenuator device can comprise: a housing component and a microwave attenuator chip, wherein the housing component can have thermal conductivity of about at least 0.1 Watts per meter-Kelvin at 1 degree Kelvin. The cryogenic microwave attenuator device can also comprise a microwave connector comprising a signal conductor that is direct wire coupled to the microwave attenuator chip.

Abstract: Techniques related to microwave attenuator son 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 thin film lines, on a top surface of the substrate, comprising an evaporated alloy. Further, the device can comprise one or more vias within the substrate. Respective first ends of the one or more vias are can be connected to respective thin film connectors. Further, respective second ends of the one or more vias can be connected to an electrical ground.

Abstract: In an embodiment, a quantum circuit (circuit) includes a first qubit and a second qubit. In an embodiment, a quantum circuit includes a tunable microwave resonator, wherein a first applied magnetic flux is configured to tune the microwave resonator to a first frequency, the first frequency configured to activate an interaction between the first qubit and the second qubit, and wherein a second applied magnetic flux is configured to tune the microwave resonator to a second frequency, the second frequency configured to minimize an interaction between the first qubit and the second qubit.

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.

Abstract: Lattice arrangements for quantum qubits are described. A lattice arrangement can comprise adjacent structures having vertices connected by edges. The qubits can be positioned on the vertices. A qubit in the lattice arrangement directly connects to not more than three other qubits, or connects to another qubit via a coupling qubit on an edge between two qubits on a vertex. The adjacent structures can comprise hexagons, dodecagons or octagons. A superconducting qubit lattice can comprise superconducting target qubits and superconducting control qubits. The superconducting qubit lattice can comprise adjacent structures having vertices connected by edges, with target qubits positioned on the vertices and control qubits positioned on the edges. Logic operations between adjacent superconducting target and control qubits can be implemented by driving the superconducting control qubit at or near the frequency of the superconducting target qubit.

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.

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 related to microwave attenuator son 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 thin film lines, on a top surface of the substrate, comprising an evaporated alloy. Further, the device can comprise one or more vias within the substrate. Respective first ends of the one or more vias are can be connected to respective thin film connectors. Further, respective second ends of the one or more vias can be connected to an electrical ground.

Abstract: A qubit may be formed by forming a Josephson junction between two capacitive plates. The Josephson junction may be an aluminum/aluminum-oxide/aluminum trilayer Josephson junction on a substrate. The Josephson junction may be annealed with a thermal source. Annealing the Josephson junction may alter the frequency of the qubit.

Abstract: Generating a layout for a multi-qubit chip is provided. A schematic is received as input. The schematic input includes a plurality of qubits, a plurality of coupling busses, a bus design parameter specifying a bus frequency, a plurality of readout busses, and a plurality of readout ports. A qubit design is selected from a qubit library, based on the qubit style in the schematic input. A bus style is selected from a bus information library, based on the bus style in the schematic input. A qubit layout is automatically generated by assembling the selected bus style/, selected qubit design, the plurality of readout busses and the plurality of readout ports.

Abstract: Verifying a quantum circuit layout design is provided. A qubit layout is received as input. The qubit layout is generated from a qubit schematic. The qubit schematic includes a plurality of qubits, a plurality of coupling buses, a plurality of readout buses, and a plurality of readout ports. Design rules checking is performed on the qubit layout input, using a predefined set of design rule. The bus style/frequency and qubit information are extracted from the qubit layout input. A new qubit schematic is generated from the extracted bus style/frequency and qubit information. The qubit layout is verified based on the new qubit schematic being the same as the qubit schematic.

Abstract: A qubit may be formed by forming a Josephson junction between two capacitive plates. The Josephson junction may be an aluminum/aluminum-oxide/aluminum trilayer Josephson junction on a substrate. The Josephson junction may be annealed with a thermal source. Annealing the Josephson junction may alter the frequency of the qubit.

Abstract: A technique relates to an assembly for a quantum computing device. A quantum bus plane includes a first set of recesses. A readout plane includes a second set of recesses. A block is positioned to hold the readout plane opposite the quantum bus plane, such that the first set of recesses opposes the second set of recesses. A plurality of qubit chips are included where each has a first end positioned in the first set of recesses and has a second end positioned in the second set of recesses.

Abstract: A technique relates to an assembly for a quantum computing device. A quantum bus plane includes a first set of recesses. A readout plane includes a second set of recesses. A block is positioned to hold the readout plane opposite the quantum bus plane, such that the first set of recesses opposes the second set of recesses. A plurality of qubit chips are included where each has a first end positioned in the first set of recesses and has a second end positioned in the second set of recesses.

Abstract: A technique relates to an assembly for a quantum computing device. A quantum bus plane includes a first set of recesses. A readout plane includes a second set of recesses. A block is positioned to hold the readout plane opposite the quantum bus plane, such that the first set of recesses opposes the second set of recesses. A plurality of qubit chips are included where each has a first end positioned in the first set of recesses and has a second end positioned in the second set of recesses.