A superconducting circuit includes a first component having a first connection point. The first connection point has a first width. The superconducting circuit includes a second component having a second connection point. The second connection point has a second width that is larger than the first width. The superconducting circuit includes a superconducting connector shaped to reduce current crowding. The superconducting connector electrically connects the first connection point and the second connection point. The superconducting connector includes a first taper positioned adjacent the first connection point and having a non-linear shape and a second taper positioned adjacent the second connection point.

An electrical joint includes a conductive member having a first mounting region configured to connect to a first conductor and a second mounting region configured to connect to a second conductor, wherein the first conductor comprises a cable and a superconducting material within the conductive member and configured to conduct a current between the first and second mounting regions. Also described is a method of forming an electrical joint, comprising forming a conductive member having a first mounting region configured to connect to a first conductor and a second mounting region configured to connect to a second conductor, wherein the first conductor comprises a cable and a superconducting material within the conductive member and configured to conduct a current between the first and second mounting regions.

Described is a partitioned cable joint comprising a plurality of physically distributed joint elements with the plurality of joint elements taken together defining a joint length. Joint elements may have a first mounting region having a shape selected to accept one petal of superconducting cable and a second mounting region having a shape selected to accept one petal of a second conductor.

Described is a partitioned cable joint comprising a plurality of physically distributed joint elements with the plurality of joint elements taken together defining a joint length. Joint elements may have a first mounting region having a shape selected to accept one petal of superconducting cable and a second mounting region having a shape selected to accept one petal of a second conductor.

A connection structure for a superconducting layer according to an embodiment includes a first superconducting layer; a second superconducting layer; and a connection layer disposed between the first superconducting layer and the second superconducting layer, the connection layer including crystal grains containing a rare earth element (RE), barium (Ba), copper (Cu), and oxygen (O), the crystal grains having a grain size distribution including a bimodal distribution. The bimodal distribution includes a first distribution including a first peak and a second distribution including a second peak. A first grain size corresponding to the first peak is larger than a second grain size corresponding to the second peak. Among the crystal grains, crystal grains having a grain size corresponding to the first distribution include a crystal grain having a plate shape or a flat shape.

A connection structure for a superconducting layer according to an embodiment includes a first superconducting layer; a second superconducting layer; and a connection layer disposed between the first superconducting layer and the second superconducting layer, the connection layer including crystal grains containing a rare earth element (RE), barium (Ba), copper (Cu), and oxygen (O), the crystal grains having a grain size distribution including a bimodal distribution. The bimodal distribution includes a first distribution including a first peak and a second distribution including a second peak. A first grain size corresponding to the first peak is larger than a second grain size corresponding to the second peak. Among the crystal grains, crystal grains having a grain size corresponding to the first distribution include a crystal grain having a plate shape or a flat shape.

A connection system for a quantum computer that employs constant impedance connectors with attenuation or filtering components or both embedded therein or within an adaptor removably insertable within an adaptor housing for use in a cryogenically cooled quantum computer. The connection system provides a higher density of cables traversing through a hermetic sealed top plate, and which are accessible to chill blocks to reduce the thermal energy from the signal lines. Attenuators or filter circuits are embedded in the constant impedance connector housings, or provided in adaptors that connect on each end to form mating constant impedance connections, in order to reduce signal strength as the signal progresses through the cryogenic environment and to remove extraneous electrical signal noise.

An electrically connecting device (1) includes a linking part defining an internal channel (12) that opens onto the exterior of the linking part. The internal channel (12) is able to receive two end segments of two superconducting wires (2, 3) that lie parallel in the internal channel (12) over a segment of common length; and an aperture (13) in the external jacket of the linking part. The aperture (13) is in communication with the internal channel (12) in order to allow a brazing material in liquid form to be inserted into the internal channel (12) around the two end segments of the two superconducting wires (2, 3).

An electrically connecting device (1) includes a linking part defining an internal channel (12) that opens onto the exterior of the linking part. The internal channel (12) is able to receive two end segments of two superconducting wires (2, 3) that lie parallel in the internal channel (12) over a segment of common length; and an aperture (13) in the external jacket of the linking part. The aperture (13) is in communication with the internal channel (12) in order to allow a brazing material in liquid form to be inserted into the internal channel (12) around the two end segments of the two superconducting wires (2, 3).

Techniques facilitating electrical coupling within cryogenic environments are provided. In one example, an electrical coupling device for a cryogenic electronics system can comprise a flexible wiring strip that includes non-superconducting wiring and a thermal break that includes superconducting wiring. The superconducting wiring can be coupled with the flexible wiring strip to bridge a gap defined, in part, by the flexible wiring strip. The superconducting wiring comprises higher electrical conductivity and lower thermal conductivity than the non-superconducting wiring.