Embodiments of the present disclosure describe integrated quantum circuit assemblies that include quantum circuit components pre-packaged, or integrated, with some other electronic components and mechanical attachment means for easy inclusion within a cooling apparatus. An example integrated quantum circuit assembly includes a package and mechanical attachment means for securing the package within a cryogenic chamber of a cooling apparatus. The package includes a plurality of components, such as a quantum circuit component, an attenuator, and a directional coupler, which are integral to the package. Such an integrated assembly may significantly speed up installation and may help develop systems for rapidly bringing up quantum computers.

A method of producing a quantum circuit includes forming a mask on a substrate to cover a first portion of the substrate, implanting a second portion of the substrate with ions, and removing the mask, thereby providing a nanowire. The method further includes forming a first lead and a second lead, the first lead and the second lead each partially overlapping the nanowire. In operation, a portion of the nanowire between the first and second leads forms a quantum dot, thereby providing a quantum dot Josephson junction. The method further includes forming a third lead and a fourth lead, one of the third and fourth leads partially overlapping the nanowire, wherein the third lead is separated from the fourth lead by a dielectric layer, thereby providing a Dolan bridge Josephson junction. The nanowire is configured to connect the quantum dot Josephson junction and the Dolan bridge Josephson junction in series.

A system for adjusting qubit frequency includes a qubit device having a Josephson junction and a shunt capacitor coupled to electrodes of the Josephson junction. A cantilevered conductor is separated from the shunt capacitor by a spacing. An adjustment mechanism is configured to deflect the cantilevered conductor to tune a qubit frequency for the qubit device.

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 quantum computing device is formed using a first chip and a second chip, the first chip having a first substrate, a first set of pads, and a set of Josephson junctions disposed on the first substrate. The second chip has a second substrate, a second set of pads disposed on the second substrate opposite the first set of pads, and a second layer formed on a subset of the second set of pads. The second layer is configured to bond the first chip and the second chip. The subset of the second set of pads corresponds to a subset of the set of Josephson junctions selected to avoid frequency collision between qubits in a set of qubits. A qubit is formed using a Josephson junction from the subset of Josephson junctions and another Josephson junction not in the subset being rendered unusable for forming qubits.

A method of producing a quantum circuit includes forming a mask on a substrate to cover a first portion of the substrate, implanting a second portion of the substrate with ions, and removing the mask, thereby providing a nanowire. The method further includes forming a first lead and a second lead, the first lead and the second lead each partially overlapping the nanowire. In operation, a portion of the nanowire between the first and second leads forms a quantum dot, thereby providing a quantum dot Josephson junction. The method further includes forming a third lead and a fourth lead, one of the third and fourth leads partially overlapping the nanowire, wherein the third lead is separated from the fourth lead by a dielectric layer, thereby providing a Dolan bridge Josephson junction. The nanowire is configured to connect the quantum dot Josephson junction and the Dolan bridge Josephson junction in series.

Embodiments of the present disclosure describe quantum circuit assemblies that include one or more filter modules integrated in a package with a quantum circuit component having at least one qubit device. Integration may be such that both the quantum circuit component and the filter module(s) are at least partially inside a chamber formed by a radiation shield structure that is configured to attenuate electromagnetic radiation incident on the quantum circuit component and the filter module(s). Placing filter modules under the protection provided by the radiation shield structure may boost coherence of the qubits. Some example filter modules may include filter(s) configured to convert electromagnetic radiation to heat and filter(s) configured to perform bandpass filtering. Modular blocks of in-line filters inside the shielded environment may allow to route signals to the quantum circuit component with reduced noise and speed up installation of a complete quantum computer.

A method of forming a thin film of material on a surface of a substrate, the substrate comprising a semiconductor, comprises: depositing a thin film of metal on the surface of the substrate, wherein the deposition is performed in an ultra-high vacuum, and wherein the substrate is at a temperature of less than or equal to 260 K during the deposition. Cooling the substrate during deposition of the thin film of metal may allow for an atomically flat and very uniform thin film to be obtained. Also provided is a device obtainable by the method.

Techniques related to a three-dimensional integration for qubits on multiple height crystalline dielectric and method of fabricating the same are provided. A superconductor structure can comprise a first buried layer that can comprise a first patterned superconducting layer of a first wafer bonded to a second patterned superconducting layer of a second wafer. The superconductor structure can also comprise a patterned superconducting film attached to the second wafer. Further, the superconductor structure can comprise a second buried layer that can comprise a third patterned superconducting layer of a third wafer bonded to the patterned superconducting film that can be attached to the second wafer.

Provided is a three-dimensional (3D) transmon qubit apparatus including a body portion, a driver, a transmon element disposed in an internal space of the body portion, a first tunable cavity module disposed in the internal space of the body, and comprising a first superconductive metal panel; and a second tunable cavity module disposed in the internal space of the body, and comprising a second superconductive metal panel, wherein the transmon element is disposed between the first superconductive metal panel and the second superconductive metal panel; wherein the first tunable cavity module and the second tunable cavity module are configured to adjust a distance between the first superconductive metal panel and the second superconductive metal panel, and wherein the driver is configured to tune a resonance frequency by adjusting a 3D cavity by adjusting the distance between the first superconductive metal panel and the second superconductive metal panel.