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.

This disclosure relates to Superconducting Quantum Interference Apparatuses, such as SQUID arrays and SQUIFs. A superconducting quantum interference apparatus comprises an array of loops each loop constituting a superconducting quantum interference device. The array comprises multiple columns, each of the columns comprises multiple rows connected in series, each of the multiple rows comprises a number of loops connected in parallel, and the number of loops connected in parallel in each row is more than two and less than 20 to improve a performance of the apparatus. It is an advantage that keeping the number of loops in parallel below 20 improves the performance of the apparatus. This is contrary to existing knowledge where it is commonly assumed that a larger number of parallel loops would increase performance.

Test structures and methods for superconducting bump bond electrical characterization are used to verify the superconductivity of bump bonds that electrically connect two superconducting integrated circuit chips fabricated using a flip-chip process, and can also ascertain the self-inductance of bump bond(s) between chips. The structures and methods leverage a behavioral property of superconducting DC SQUIDs to modulate a critical current upon injection of magnetic flux in the SQUID loop, which behavior is not present when the SQUID is not superconducting, by including bump bond(s) within the loop, which loop is split among chips. The sensitivity of the bump bond superconductivity verification is therefore effectively perfect, independent of any multi-milliohm noise floor that may exist in measurement equipment.

A solid state cooler device is disclosed that comprises a first normal metal pad, a first aluminum layer and a second aluminum layer disposed on the first normal metal pad and separated from one another by a gap, a first aluminum oxide layer formed on the first aluminum layer, and a second aluminum oxide layer formed on the second aluminum layer, and a first superconductor pad disposed on the first aluminum oxide layer and a second superconductor pad disposed on the second aluminum oxide layer. The device further comprises a first conductive pad coupled to the first superconductor pad, and a second conductive pad coupled to the second superconductor pad, wherein hot electrons are removed from the first normal metal pad when a bias voltage is applied between the first conductive pad and the second conductive pad.

A resonator, an oscillator, and a quantum computer capable of preventing oscillation conditions for generating a parametric oscillation from becoming complicated are provided. A resonator includes at least one loop circuit in which a first superconducting line, a first Josephson junction, a second superconducting line, and a second Josephson junction are connected in a ring shape, in which critical current values of the first and second Josephson junctions are different from each other.

A carrier is provided for quantum computer chips that allows easy implementation, connection, and communication to and from the quantum computer chips while minimizing the thermal perturbation and avoiding labor intensive manual connection as well as the human error in such manual connection. Methods for fabricating such carriers are also provided.

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 technique relates to a superconducting chip. Resonant units have resonant frequencies, and the resonant units are configured as superconducting resonators. Josephson junctions are in the resonant units, and one or more of the Josephson junctions have a shorted tunnel barrier.

A solid state cooler device is provided that includes a substrate, a first and second conductive pad disposed on the substrate, a first and second superconductor pad each having a side with a plurality of conductive pad contact interfaces spaced apart from one another and being in contact with a surface of respective first and second conductive pads, and a first and second insulating layer disposed between respective first and second superconductor pads, and respective ends of a normal metal layer. A bias voltage is applied between one of a first conductive pad or first superconductor pad and one of the second conductive pad or the second superconductor pad to remove hot electrons from the normal metal layer, and the contact area of the plurality of first and second conductive pad contact interfaces inhibits the transfer of heat back to the first and second superconductor pads.

Test structures and methods for superconducting bump bond electrical characterization are used to verify the superconductivity of bump bonds that electrically connect two superconducting integrated circuit chips fabricated using a flip-chip process, and can also ascertain the self-inductance of bump bond(s) between chips. The structures and methods leverage a behavioral property of superconducting DC SQUIDs to modulate a critical current upon injection of magnetic flux in the SQUID loop, which behavior is not present when the SQUID is not superconducting, by including bump bond(s) within the loop, which loop is split among chips. The sensitivity of the bump bond superconductivity verification is therefore effectively perfect, independent of any multi-milliohm noise floor that may exist in measurement equipment.