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 mixed semiconductor-superconductor platform is fabricated in phases. In a masking phase, a dielectric mask is formed on a substrate, such that the dielectric mask leaves one or more regions of the substrate exposed. In a selective area growth phase, a semiconductor material is selectively grown on the substrate in the one or more exposed regions. In a superconductor growth phase, a layer of superconducting material is formed, at least part of which is in direct contact with the selectively grown semiconductor material. The mixed semiconductor-superconductor platform comprises the selectively grown semiconductor material and the superconducting material in direct contact with the selectively grown semiconductor material.

A mixed semiconductor-superconductor platform is fabricated in phases. In a masking phase, a dielectric mask is formed on a substrate, such that the dielectric mask leaves one or more regions of the substrate exposed. In a selective area growth phase, a semiconductor material is selectively grown on the substrate in the one or more exposed regions. In a superconductor growth phase, a layer of superconducting material is formed, at least part of which is in direct contact with the selectively grown semiconductor material. The mixed semiconductor-superconductor platform comprises the selectively grown semiconductor material and the superconducting material in direct contact with the selectively grown semiconductor material.

A tunable dissipative circuit is presented for shifting a frequency of a radio frequency signal or microwave signal in a cryogenically cooled environment. One or more couplers make couplings between a propagation path and a tunable resonance element and a controllable dissipator element. A first control input to said tunable resonance element allows changing a resonance frequency of said tunable resonance element with a first control signal. A second control input to said controllable dissipator element allows changing a damping rate of said controllable dissipator element with a second control signal.

A tunable dissipative circuit is presented for shifting a frequency of a radio frequency signal or microwave signal in a cryogenically cooled environment. One or more couplers make couplings between a propagation path and a tunable resonance element and a controllable dissipator element. A first control input to said tunable resonance element allows changing a resonance frequency of said tunable resonance element with a first control signal. A second control input to said controllable dissipator element allows changing a damping rate of said controllable dissipator element with a second control signal.

An electronic device (e.g., a diode) is provided that includes a substrate and a patterned layer of superconducting material disposed over the substrate. The patterned layer forms a first electrode, a second electrode, and a loop coupling the first electrode with the second electrode by a first channel and a second channel. The first channel and the second channel have different minimum widths. The device further includes a magnet that applies a magnetic field to the loop, which produces an expulsion current in the loop that travels toward the second electrode in the first channel and toward the first electrode in the second channel. For a range of current magnitudes, when the magnetic field is applied to the patterned layer of superconducting material, the conductance from the first electrode to the second electrode is greater than the conductance from the second electrode to the first electrode.

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 cryogenic electronic package includes a first superconducting multi-chip module (SMCM), a superconducting interposer, a second SMCM and a superconducting semiconductor structure. The interposer is disposed over and coupled to the first SMCM, the second SMCM is disposed over and coupled to the interposer, and the superconducting semiconductor structure is disposed over and coupled to the second SMCM. The second SMCM and the superconducting semiconductor structure are electrically coupled to the first SMCM through the interposer. A method of fabricating a cryogenic electronic package is also provided.

A structure includes a first device having a first chip and a second chip. The second chip has a first side with a plurality of bumps and a second side with a plurality of first superconducting lines. A solder bonded layer attaches the first chip to the second chip. A second device has a first side with a plurality of pads facing the plurality of bumps in the second chip and a second side opposite the first side having a plurality of second superconducting lines. A solder shield material surrounds the plurality of bumps and the plurality of pads, and the plurality of bumps on the second chip are bonded to the plurality of pads on the second device. The solder shield material is connected to the plurality of first superconducting lines of the first device and to the plurality of second superconducting lines of the second device.

A structure includes a first device having a first chip and a second chip. The second chip has a first side with a plurality of bumps and a second side with a plurality of first superconducting lines. A solder bonded layer attaches the first chip to the second chip. A second device has a first side with a plurality of pads facing the plurality of bumps in the second chip and a second side opposite the first side having a plurality of second superconducting lines. A solder shield material surrounds the plurality of bumps and the plurality of pads, and the plurality of bumps on the second chip are bonded to the plurality of pads on the second device. The solder shield material is connected to the plurality of first superconducting lines of the first device and to the plurality of second superconducting lines of the second device.