Abstract: 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.

Abstract: A technique relates to a superconducting chip. Resonant units each include a Josephson junction. The resonant units have resonant frequencies whose differences are based on a variation in the Josephson junction. A transmission medium is coupled to the resonant units, and the transmission medium is configured to output a sequence of the resonant frequencies as an identification of the chip.

Abstract: Techniques related to vertical silicon-on-metal superconducting quantum interference devices and method of fabricating the same are provided. Also provided are associated flux control and biasing circuitry. A superconductor structure can comprise a silicon-on-metal substrate that can comprise a first superconducting layer, comprising a first superconducting material, between a first crystalline silicon layer and a second crystalline silicon layer. The superconducting structure can also comprise a first via comprising a first Josephson junction and a second via comprising a second Josephson junction. The first via and the second via can be formed between the first superconducting layer and a second superconducting layer, comprising a second superconducting material.

Abstract: A technique relates to a superconducting chip. Resonant units each include a Josephson junction. The resonant units have resonant frequencies whose differences are based on a variation in the Josephson junction. A transmission medium is coupled to the resonant units, and the transmission medium is configured to output a sequence of the resonant frequencies as an identification of the chip.

Abstract: On a first superconducting layer deposited on a first surface of a substrate, a first component of a resonator is pattered. On a second superconducting layer deposited on a second surface of the substrate, a second component of the resonator is patterned. The first surface and the second surface are disposed relative to each other in a non-co-planar disposition. In the substrate, a recess is created, the recess extending from the first superconducting layer to the second superconducting layer. On an inner surface of the recess, a third superconducting layer is deposited, the third superconducting layer forming a superconducting path between the first superconducting layer and the second superconducting layer. Excess material of the third superconducting layer is removed from the first surface and the second surface, forming a completed through-silicon via (TSV).

Abstract: Techniques related to a three-dimensional integration for qubits on crystalline dielectric and method of fabricating the same are provided. A superconductor structure can comprise a first wafer comprising a first crystalline silicon layer attached to a first patterned superconducting layer, and a second wafer comprising a second crystalline silicon layer attached to a second patterned superconducting layer. The second patterned superconducting layer of the second wafer can be attached to the first patterned superconducting layer of the first wafer. A buried layer can comprise the first patterned superconducting layer and the second patterned superconducting layer. The buried layer can comprise one or more circuits. The superconductor structure can also comprise a transmon qubit that can comprise a Josephson junction and one or more capacitor pads comprising superconducting material. The Josephson junction can comprise a first superconductor contact, a tunnel barrier layer, and a second superconductor contact.

Abstract: A capacitive coupling device (superconducting C-coupler) includes a trench formed through a substrate, from a backside of the substrate, reaching a depth in the substrate, substantially orthogonal to a plane of fabrication on a frontside of the substrate, the depth being less than a thickness of the substrate. A superconducting material is deposited as a continuous conducting via layer in the trench with a space between surfaces of the via layer in the trench remaining accessible from the backside. A superconducting pad is formed on the frontside, the superconducting pad coupling with a quantum logic circuit element fabricated on the frontside. An extension of the via layer is formed on the backside. The extension couples to a quantum readout circuit element fabricated on the backside.

Abstract: A technique relates to forming a sidewall tunnel junction. A first conducting layer is formed using a first shadow mask evaporation. A second conducting layer is formed on a portion of the first conducting layer, where the second conducting layer is formed using a second shadow mask evaporation. An oxide layer is formed on the first conducting layer and the second conducting layer. A third conducting layer is formed on part of the oxide layer, such that the sidewall tunnel junction is positioned between the first conducting layer and the third conducting layer.

Abstract: A technique relates to forming a sidewall tunnel junction. A first conducting layer is formed using a first shadow mask evaporation. A second conducting layer is formed on a portion of the first conducting layer, where the second conducting layer is formed using a second shadow mask evaporation. An oxide layer is formed on the first conducting layer and the second conducting layer. A third conducting layer is formed on part of the oxide layer, such that the sidewall tunnel junction is positioned between the first conducting layer and the third conducting layer.

Abstract: Techniques for a vertical Josephson junction superconducting device are provided. In one embodiment, a chip surface base device structure is provided that comprises a substrate comprising crystalline silicon that is coupled with a first superconducting layer, wherein the first superconducting layer is coupled with a second substrate comprising crystalline silicon. In one implementation, the chip surface base device structure also comprises a vertical Josephson junction located in an etched region of the substrate, the vertical Josephson junction comprising a first superconducting layer, a tunnel barrier layer, and a top superconducting layer.

Abstract: Methods and systems for generating an identifier includes testing an operational characteristic for each device in an array of pairs of devices. Each pair of devices includes a first device and a second device. The first device of each pair has a higher inter-device uniformity for the operational characteristic than the second device of the pair. The operational characteristic between the first device and the second device is compared for each pair of devices to generate a respective identifier bit for each pair of devices. An identifier is generated from the identifier bits.

Abstract: Systems and techniques facilitating antenna-based thermal annealing of qubits are provided. In one example, a radio frequency emitter, transmitter, and/or antenna can be positioned above a superconducting qubit chip having a Josephson junction coupled to a set of one or more capacitor pads. The radio frequency emitter, transmitter, and/or antenna can emit an electromagnetic signal onto the set of one or more capacitor pads. The capacitor pads can function as receiving antennas and therefore receive the electromagnetic signal. Upon receipt of the electromagnetic signal, an alternating current and/or voltage can be induced in the capacitor pads, which current and/or voltage thereby heat the pads and the Josephson junction. The heating of the Josephson junction can change its physical properties, thereby annealing the Josephson junction. In another example, the emitter can direct the electromagnetic signal to avoid unwanted annealing of neighboring qubits on the superconducting qubit chip.

Abstract: Methods and systems for generating an identifier include detecting emissions from a phosphor pattern with a sensor grid comprising one or more sensors when the phosphor pattern is stimulated with radiation. An output signal of each sensor in the sensor grid is compared to a threshold value to generate respective identifier bits. An identifier is generated from the identifier bits.

Abstract: Techniques for a vertical transmon qubit device are provided. In one embodiment, a chip surface base device structure is provided that comprises a first superconducting material physically coupled to a crystalline substrate, wherein the crystalline substrate is physically coupled to a second superconducting material, wherein the second superconducting material is physically coupled to a second crystalline substrate. In one implementation, the chip surface base device structure also comprises a vertical Josephson junction located in a via of the crystalline substrate, the vertical Josephson junction comprising the first superconducting material, a tunnel barrier, and the second superconducting material. In one implementation, the chip surface base device structure also comprises a transmon qubit comprising the vertical Josephson junction and a capacitor formed between the first superconducting material and the second superconducting material.

Abstract: A semiconductor structure includes fins that have a 2D material, such as Graphene, upon at least the fin sidewalls. The thickness of the 2D material sidewall may be tuned to achieve desired finFET band gap control. Neighboring fins of the semiconductor structure form fin wells. The semiconductor structure may include a fin cap upon each fin and the 2D material is formed upon the sidewalls of the fin and the bottom surface of the fin wells. The semiconductor structure may include a well-plug at the bottom of the fin wells and the 2D material is formed upon the sidewalls and upper surface of the fins. The semiconductor structure may include both fin caps and well-plugs such that the 2D material is formed upon the sidewalls of the fins.

Abstract: A technique relates to forming a sidewall tunnel junction. A first conducting layer is formed using a first shadow mask evaporation. A second conducting layer is formed on a portion of the first conducting layer, where the second conducting layer is formed using a second shadow mask evaporation. An oxide layer is formed on the first conducting layer and the second conducting layer. A third conducting layer is formed on part of the oxide layer, such that the sidewall tunnel junction is positioned between the first conducting layer and the third conducting layer.

Abstract: Systems and techniques facilitating antenna-based thermal annealing of qubits are provided. In one example, a radio frequency emitter, transmitter, and/or antenna can be positioned above a superconducting qubit chip having a Josephson junction coupled to a set of one or more capacitor pads. The radio frequency emitter, transmitter, and/or antenna can emit an electromagnetic signal onto the set of one or more capacitor pads. The capacitor pads can function as receiving antennas and therefore receive the electromagnetic signal. Upon receipt of the electromagnetic signal, an alternating current and/or voltage can be induced in the capacitor pads, which current and/or voltage thereby heat the pads and the Josephson junction. The heating of the Josephson junction can change its physical properties, thereby annealing the Josephson junction. In another example, the emitter can direct the electromagnetic signal to avoid unwanted annealing of neighboring qubits on the superconducting qubit chip.

Abstract: Techniques for a vertical Josephson junction superconducting device using microstrip waveguides are provided. In one embodiment, a chip surface base device structure is provided that comprises a superconducting material located on a first side of a substrate, and a second superconducting material located on a second side of the substrate and stacked on a second substrate, wherein the first side of the substrate and the second side of the substrate are opposite sides. In one implementation, the substrate or the second substrate, or the substrate and the second substrate are crystalline silicon. In one implementation, the chip surface base device structure also comprises a transmon qubit comprising a capacitor and a Josephson junction formed in a via of the substrate and comprising a tunnel barrier. In one implementation, the chip surface base device structure also comprises a microstrip line electrically coupled to the transmon qubit.

Abstract: Techniques for a vertical Josephson junction superconducting device using microstrip waveguides are provided. In one embodiment, a chip surface base device structure is provided that comprises a superconducting material located on a first side of a substrate, and a second superconducting material located on a second side of the substrate and stacked on a second substrate, wherein the first side of the substrate and the second side of the substrate are opposite sides. In one implementation, the substrate or the second substrate, or the substrate and the second substrate are crystalline silicon. In one implementation, the chip surface base device structure also comprises a transmon qubit comprising a capacitor and a Josephson junction formed in a via of the substrate and comprising a tunnel barrier. In one implementation, the chip surface base device structure also comprises a microstrip line electrically coupled to the transmon qubit.

Abstract: A tunable qubit device includes a tunable qubit, the tunable qubit including a superconducting quantum interference device (SQUID) loop. The tunable qubit device further includes a superconducting loop inductively coupled to the SQUID loop, and a flux bias line inductively coupled to the superconducting loop. The superconducting loop includes a superconducting material having a critical temperature that is a lower temperature than a critical temperature of any superconducting material of the tunable qubit. In operation, the superconducting loop provides a persistent bias to the tunable qubit.