In an embodiment, a quantum device includes a first set of protrusions formed on a substrate and a second set of protrusions formed on a qubit chip. In the embodiment, the quantum device includes a set of bumps formed on an interposer, the set of bumps formed of a material having above a threshold ductility at a room temperature range, wherein a first subset of the set of bumps is configured to cold weld to the first set of protrusions and a second subset of the set of bumps is configured to cold weld to the second set of protrusions.

A superconducting electrical device includes one or more traveling-wave parametric amplifiers (TWPAs) on a chip that is electrically connected to a wiring layer of a substrate. The electrical connection of the chip to the wiring layer of the substrate includes, for each of the one or more TWPAs, a signal bump-bond between the TWPA and the substrate. There is a peripheral ring of ground bumps around the signal bump between the TWPA and the substrate.

A method for adjusting a resonance frequency of a qubit in a quantum mechanical device includes providing a substrate having a frontside and a backside, the frontside having at least one qubit formed thereon, the at least one qubit comprising capacitor pads; and removing substrate material from the backside of the substrate at an area opposite the at least one qubit to alter a capacitance around the at least one qubit so as to adjust a resonance frequency of the at least one qubit.

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.

Provided is a quantum device capable of improving cooling performance. A quantum device includes a quantum chip configured to perform information processing using a quantum state, and an interposer on which the quantum chip is mounted, and the quantum chip is arranged inside a recess 31 formed in a sample stage having a cooling function, and a part of the interposer is in contact with the sample stage. The quantum chip may have a first surface mounted on the interposer and a second surface opposite to the first surface, and at least a part of the second surface may be in contact with an inner surface of the recess.

A functional chip includes a substrate including a first face and a second face, the second face of the substrate forming the front face of the functional chip; a first oxide layer on the first face of the substrate; a second oxide layer on the first oxide layer; a first routing level formed on the surface of the second oxide layer in contact with the first oxide layer; a third oxide layer on the second oxide layer wherein a semiconductor component is inserted; a rear face formed by the surface of the third oxide layer opposite the second oxide layer, the rear face including superconductor routing tracks surrounded at least partially by one or more conductor routing tracks, the semiconductor component being connected to the superconductor routing tracks via superconductor vias and the conductor routing tracks of the rear face being connected to the routing level via conductor vias.

A method for bonding two superconducting integrated circuits (“chips”), such that the bonds electrically interconnect the chips. A plurality of indium-coated metallic posts may be deposited on each chip. The indium bumps are aligned and compressed with moderate pressure at a temperature at which the indium is deformable but not molten, forming fully superconducting connections between the two chips when the indium is cooled down to the superconducting state. An anti-diffusion layer may be applied below the indium bumps to block reaction with underlying layers. The method is scalable to a large number of small contacts on the wafer scale, and may be used to manufacture a multi-chip module comprising a plurality of chips on a common carrier. Superconducting classical and quantum computers and superconducting sensor arrays may be packaged.

Devices, systems, methods, computer-implemented methods, apparatus, and/or computer program products that can facilitate an epitaxial Josephson junction transmon device are provided. According to an embodiment, a device can comprise a substrate. The device can further comprise an epitaxial Josephson junction transmon device coupled to the substrate. According to an embodiment, a device can comprise an epitaxial Josephson junction transmon device coupled to a substrate. The device can further comprise a tuning gate coupled to the substrate and formed across the epitaxial Josephson junction transmon device. According to an embodiment, a device can comprise a first superconducting region and a second superconducting region formed on a substrate. The device can further comprise an epitaxial Josephson junction tunneling channel coupled to the first superconducting region and the second superconducting region.

An integrated circuit is provided that comprises a first substrate having a plurality of conductive contact pads spaced apart from one another on a surface of the first substrate, a dielectric layer overlying the first substrate and the plurality of conductive contact pads, and a second substrate overlying the dielectric layer. A plurality of superconducting contacts extend through the second substrate and the dielectric layer to the first substrate, wherein each superconducting contact of the plurality of superconducting contacts is aligned with and in contact with a respective conductive contact pad of the plurality of conductive contact pads.

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.