A semiconductor device includes a transmission circuit coupled between a first voltage supply node and a second voltage supply node, and suitable for outputting an output data signal corresponding to a data value to an output terminal during a data output enable period, and a switching circuit coupled between the first and second voltage supply nodes, and suitable for providing a current path between the first and second voltage supply nodes during a data output disable period.

A device that is a combination of a superconducting nanowire single-photon detector and a superconducting multi-level memory. These devices can be used to count a number of photons impinging on the device through single-photon to single-flux conversion. Electrical characterization of the device demonstrates single-flux quantum (SFQ) separated states. Optical measurements using attenuated laser pulses with different mean photon number, pulse energies and repetition rates are shown to differentiate single-photon detection from other possible phenomena, such as multiphoton detection and thermal activation. Array devices and methods are also discussed.

Conventional readout of a superconducting nanowire single-photon detector (SNSPD) sets an upper bound on the output voltage to be the product of the bias current and the load impedance, I.sub.BZ.sub.load, where Z.sub.load is limited to 50 in standard RF electronics. This limit is broken/exceeded by interfacing the 50 load and the SNSPD using an integrated superconducting transmission line taper. The taper is a transformer that effectively loads the SNSPD with high impedance without latching. The taper increases the amplitude of the detector output while preserving the fast rising edge. Using a taper with a starting width of 500 nm, a 3.6 higher pulse amplitude, 3.7 faster slew rate, and 25.1 ps smaller timing jitter was observed. The taper also makes the detector's output voltage sensitive to the number of photon-induced hotspots and enables photon number resolution.

A quantum computing device is fabricated by forming, on a superconductor layer, a first resist pattern defining a device region and a sensing region within the device region. The superconductor layer within the sensing region is removed, exposing a region of an underlying semiconductor layer outside the device region. The exposed region of the semiconductor layer is implanted, forming an isolation region surrounding the device region. Using an etching process subsequent to the implanting, the sensing region and a portion of the device region of the superconductor layer adjacent to the isolation region are exposed. By depositing a first metal layer within the sensing region, a tunnel junction gate is formed. A reflectrometry wire comprising a second metal within the reflectrometry region is formed. A nanorod contact using the second metal within the portion of the device region outside the sensing region is formed.

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.

The present invention relates to a superconducting nanowire single-photon detector, which can include a superconducting nanowire configured and arranged for the incidence of a photon on a region thereof and the formation, on that region, of a localized non-superconducting region or hotspot.

The superconducting nanowire is made of a high-Tc cuprate superconductor material having a superconducting critical temperature above 77 K.

The present invention also relates to a method for obtaining the superconducting nanowire single-photon detector of the present invention.

A photon source includes a photo-pair generator and a detection device. The photo-pair generator is configured to generate a photon-pair in receiving an input signal. A first photon of the photon-pair is output from the photon source via a first optical path. The detection device is configured to receive a second photon of the photon-pair. The detection device includes a transistor that has a semiconducting component that is a source and a drain of the transistor, and a superconducting component that is adjacent to the semiconducting component and is a gate of the transistor. The transistor is configured to transition from an off state to an on state in response a photon being incident upon the detection device.

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.

An active three-terminal superconducting device having an intersection region at which a hot spot may be controllably formed is described. The intersection region may exhibit current crowding in response to imbalances in current densities applied to channels connected to intersection region. The current crowding may form a hot spot, in which the superconducting device may exhibit a measurable resistance. In some cases, a three-terminal superconducting device may be configured to sense an amount of superconducting current flowing in a channel or loop without having to perturb the superconducting state or amount of current flowing in the channel. A three-terminal superconducting device may be used to read out a number of fluxons stored in a superconducting memory element.

According to an embodiment, a radiation detector includes a plurality of absorbers, a resistor, and a heat bath member. The absorbers absorb radiation. The resistor undergoes a change in resistance according to a change in temperature of the absorbers. The heat bath member is maintained at a temperature at which resistance of the resistor becomes equal to a specific resistance value, and is positioned to be in thermal contact with the resistor. The absorbers are positioned to be in contact with the resistor, and are arranged at a distance from each other.