Aspects of the present disclosure generally pertain to a magnetic field sensor with flex coupling structures. Aspects of the present disclosure are more specifically directed toward Nanoscale Superconducting Quantum Interference Devices (nanoSQUIDs) with very low white flux noise characteristics can be fashioned into very sensitive magnetic field sensors by using external structures to increase the amount of flux that passes through the nanoSQUID aperture. One such structure is a superconducting coupling loop that shares part of a circuit with the nanoSQUID, and couples flux into the nanoSQUID primarily through kinetic inductance rather than geometric inductance.

Superconducting integrated circuits with clock signals distributed via an inductive coupling and related methods are provided. A method includes providing a D flip-flop having a clock terminal coupled to receive clock pulses from a clock line, a data input terminal, and a data output terminal. The D flip-flop may further include a first Josephson junction (JJ) coupled between a first terminal and a second terminal. The D flip-flop may further include a superconducting quantum interference device (SQUID) coupled between a third terminal and a fourth terminal, where an inductive loop, formed between the first JJ and the SQUID, is configured to in response to receiving a first clock pulse, store a fluxon when a state of the input data signal is high, and is configured to in response to receiving a second clock pulse to annihilate the stored fluxon when a state of the input data signal is low.

A biomagnetic field measurement device to measure a biomagnetic field includes a superconducting quantum interference device (SQUID) sensor, and includes a flux locked loop unit. The SQUID sensor includes an adjustment device configured to adjust a loop gain of the flux locked loop unit.

A quantum computing device includes multiple co-planar waveguide flux qubits, at least one coupler element arranged such that each co-planar waveguide flux qubit, of the multiple co-planar waveguide flux qubits, is operatively couplable to each other co-planar waveguide flux qubit, of the multiple co-planar waveguide flux qubits, of the quantum computing device, and a tuning quantum device, in which the tuning quantum device is in electrical contact with a first co-planar waveguide flux qubit of the plurality of co-planar waveguide flux qubits and with a second co-planar waveguide flux qubit of the plurality of co-planar waveguide flux qubits.

A magnetic field measuring apparatus includes an A/D conversion unit, an integration unit, and a post-processing unit. The A/D conversion unit is configured to sample a signal at a predetermined sampling frequency and perform conversion into digital data, the signal being based on an output voltage from a superconducting quantum interference device configure to detect a magnetic field emanating from a living organism. The integration unit is configured to obtain a biological magnetic field signal based on a value obtained by integrating the digital data, the biological magnetic field signal indicating a magnetic field emanating from the living organism. The post-processing unit is configured to perform decimation processing on the biological magnetic field signal output from the integration unit.

A magnetometer for measuring a magnetic flux and also the absolute magnetic flux, the magnetometer comprising a plurality of superconducting quantum devices (SQUIDs) connected in series, each SQUID including: a superconducting loop containing two Josephson junctions connected to each other in parallel; and a flux-focussing region, the flux-focussing region configured to generate a screening current in response to the magnetic flux, the screening current modulating the corresponding voltage response for each SQUID which is in-phase with the voltage response of each other SQUID in the array.

A two-dimensional SQIF array and methods for manufacture can include at least two bi-SQUIDs that share an inductance. The bi-SQUIDs can be combined to establish a diamond-shaped cell. A plurality of the diamond shaped cells can be packed tightly together so that each cell shares at least three cell junctions with adjacent cells to establish the SQIF array. Because of the close proximity of the cells, the effect that the mutual inductances each cell has on adjacent cells can be accounted for, as well as the SQIF array boundary conditions along the array edges. To do this, a matrix of differential equations can be solved to provide for the recommended inductance of each bi-SQUID in the SQIF array. Each bi-SQUID can be manufactured with the recommended inductance to result in a SQIF having an increased strength of anti-peak response, but without sacrificing the linearity of the response.

One example includes a superconducting readout system. The system includes an RF hybrid coupler configured to receive an RF input signal and to generate at least one RF tuning signal and an RF output signal based on the RF input signal. The system also includes at least one tunable resonator system comprising a tunable resonator configured to receive the respective RF tuning signal(s). Each of the tunable resonator(s) can have a resonant frequency that is set by a superconducting input signal, such that the RF tuning signal(s) is reflected back to the RF hybrid coupler to provide a variable phase-shift of the RF output signal relative to the RF input signal that is based on the superconducting input signal. The system further includes a phase monitor configured to measure a phase difference between the RF input signal and the RF output signal to determine the superconducting input signal.

A qubit interaction circuit includes a first qubit device, a second qubit device, a first resonator, a second resonator, a first capacitor coupling the first qubit device to the first resonator and a second capacitor coupling the second qubit device to the second resonator. An rf-SQUID circuit includes an rf-SQUID loop, an rf-SQUID controller, and a dc-SQUID loop. The rf-SQUID controller is configured to influence a first flux of the rf-SQUID loop and the dc-SQUID loop, the rf-SQUID circuit coupling the first resonator with the second resonator. A dc-SQUID controller is configured to influence a second flux of the rf-SQUID loop and the dc-SQUID loop.

A processing system includes: at least one memory storing instructions; and at least one processor configured to execute the instructions to: calculate a first current value based on a value of a residual magnetic flux in a resonator circuit included in a quantum bit device, the first current value being a current value of a current flowing through the resonator circuit.