A flex circuit board can be used in transmitting signals in a quantum computing system. The flex circuit board can include at least one dielectric layer and at least one superconducting layer disposed on a surface of the at least one dielectric layer. The at least one superconducting layer can include a superconducting material. The superconducting material can be superconducting at a temperature less than about 3 kelvin. The flex circuit board can have at least one metal structure electroplated onto the at least one superconducting layer.

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 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 system and method for the automatic placement of superconducting devices determines an arrangement of a series of Josephson junctions between a start point and an end point of an inductive wiring run on a superconducting circuit layout having a plurality of discrete Josephson junction placement sites by determining costs of placing each Josephson junction of the series of Josephson junctions at the plurality of discrete Josephson junction placement sites between the start point and the end point of the inductive wiring run based at least on a comparison of a target inductance value to inductances of wires connecting to the Josephson junction and selecting sites from the plurality of discrete Josephson junction placement sites to place each Josephson junction corresponding to the arrangement of the series of Josephson junctions with the least determined cost for the inductive wiring run.

A strip conductor device includes first and second elongated strip conductor elements, each configured to be coupled at a coupling-in end to a contact device for coupling-in electric current and at a coupling-out end to a contact device for coupling-out electric current. The first elongated strip conductor element is a first strip conductor that has a substrate layer that carries a conductor layer that has barrier elements along a length of the conductor layer. The second elongated strip conductor element is a second strip conductor that has a substrate layer that carries a conductor layer that has barrier elements along a length of the conductor layer. The first strip conductor element forms a layer arrangement with the second strip conductor element and the coupling-in ends and the coupling-out ends of the first and second strip conductor elements lie one above the other.

A strip conductor device includes first and second elongated strip conductor elements, each configured to be coupled at a coupling-in end to a contact device for coupling-in electric current and at a coupling-out end to a contact device for coupling-out electric current. The first elongated strip conductor element is a first strip conductor that has a substrate layer that carries a conductor layer that has barrier elements along a length of the conductor layer. The second elongated strip conductor element is a second strip conductor that has a substrate layer that carries a conductor layer that has barrier elements along a length of the conductor layer. The first strip conductor element forms a layer arrangement with the second strip conductor element and the coupling-in ends and the coupling-out ends of the first and second strip conductor elements lie one above the other.

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.