Techniques for creating an offset embedded ground plane cutout for a qubit device to facilitate frequency tuning of the qubit device are presented. A qubit device can comprise a first substrate and second substrate in a flip-chip assembly. The qubit chip assembly can comprise a qubit component fabricated on the first substrate. The qubit component can comprise a Josephson junction (JJ) circuit that can be offset from a center point of the qubit component. The qubit chip assembly can comprise an embedded ground plane situated on a surface of the qubit chip assembly. A cutout section can be formed in the ground plane and positioned over the JJ circuit. The cutout section can enable access of an optical signal or magnetic flux to the JJ circuit. A frequency of the qubit component can be tuned based on application of the optical signal or magnetic flux to the JJ circuit.

An integrated qubit readout circuit is presented, which includes a superconducting parametric amplifier, a circuit board arranged to mount the superconducting parametric amplifier, a circulator mounted on the circuit board and connected to the superconducting parametric amplifier, wherein the circulator comprises a termination port electrically connected to a termination resistor arranged to terminate a pump tone received by the superconducting parametric amplifier, and wherein the termination resistor is mounted on the circuit board.

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.

Devices, systems, methods, and/or computer-implemented methods that can facilitate a qubit device comprising a superconducting circuit provided on an encapsulated vacuum cavity are provided. According to an embodiment, a device can comprise a substrate having an encapsulated vacuum cavity provided on the substrate. The device can further comprise a superconducting circuit provided on the encapsulated vacuum cavity.

Systems and techniques that facilitate uniform qubit chip gaps via injection-molded solder pillars are provided. In various embodiments, a device can comprise one or more injection-molded solder interconnects. In various aspects, the one or more injection-molded solder interconnects can couple at least one qubit chip to an interposer chip. In various embodiments, the device can further comprise one or more injection-molded solder pillars. In various instances, the one or more injection-molded solder pillars can be between the at least one quit chip and the interposer chip. In various cases, the one or more injection-molded solder pillars can be in parallel with the one or more injection-molded solder interconnects. In various embodiments, the one or more injection-molded solder pillars can facilitate and/or maintain a uniform gap between the at least one qubit chip and the interposer chip. In various embodiments, a melting point of the one or more injection-molded solder pillars can be higher than a melting point of the one or more injection-molded solder interconnects. In various embodiments, the one or more injection-molded solder pillars can be superconductors. In various embodiments, a yield strength of the one or more injection-molded solder pillars can be between 3,000 pounds per square inch and 15,000 pounds per square inch, which can be higher than a yield strength of the one or more injection-molded solder interconnects. In various embodiments, the one or more injection-molded solder pillars can be binary tin alloys, tertiary tin alloys, and/or quaternary tin alloys.

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 quantum device includes a qubit chip having a plurality of qubits and an interposer attached to and electrically connected to the qubit chip. The device also includes a substrate handler attached to one side of the qubit chip or to one side of the interposer, or both so as to be thermally in contact with the qubit chip or the interposer, or both. The substrate handler includes a plurality of vias, at least a portion of plurality of vias being filled with a non-superconducting material, the non-superconducting material being selected to dissipate heat generated in the qubit chip, the interposer or both.

A device includes a first chip having a first circuit element, a first interconnect pad in electrical contact with the first circuit element, and a barrier layer on the first interconnect pad, a superconducting bump bond on the barrier layer, and a second chip joined to the first chip by the superconducting bump bond, the second chip having a first quantum circuit element, in which the superconducting bump bond provides an electrical connection between the first circuit element and the first quantum circuit element.

A device includes a first chip having a first circuit element, a first interconnect pad in electrical contact with the first circuit element, and a barrier layer on the first interconnect pad, a superconducting bump bond on the barrier layer, and a second chip joined to the first chip by the superconducting bump bond, the second chip having a first quantum circuit element, in which the superconducting bump bond provides an electrical connection between the first circuit element and the first quantum circuit element.

A flux-biasing device includes a set of magnetic flux generating members. A first magnetic flux generating member is configured to magnetically interact with a first qubit from a set of qubits of a quantum processor such that a first magnetic flux of the first member causes a first change in a first resonance frequency of the first qubit by a first frequency shift value. Each non-corresponding magnetic flux generating member of the set is well separated from qubits corresponding to other magnetic flux generating members of the set such that qubits corresponding to other members exhibit less than a threshold value of resonance frequency shift as a result of a magnetic flux of a non-corresponding member.