We present the first experimental realization of a widely frequency tunable, nondegenerate three-wave mixing device for quantum signals at gigahertz frequency. It is based on a new superconducting building block consisting of a ring of four Josephson junctions shunted by a cross of four linear inductances. The phase configuration of the ring remains unique over a wide range of magnetic fluxes t...

A novel superconducting neuron circuit and two types of variable synapses, which are based on superconducting quantum interferometer devices (SQUIDS), are presented. A neuron circuit with good input-output isolation and steep threshold characteristics is accomplished using a combination of a single-junction SQUID coupled to a double-junction SQUID. The quantum state of the single-junction SQUID...

We propose a semiconductor-superconductor hybrid device for realizing topological superconductivity and Majorana zero modes consisting of planar Josephson junction structure with periodically modulated width. By performing numerical analysis the effective model describing low-energy physics structure, we demonstrate that modulation width results in substantial enhancement gap and, consequently,...

We suggest a system in which the amplitude of macroscopic flux tunneling can be modulated via the Aharonov-Casher effect. The system is an rf SQUID with the Josephson junction replaced by a Bloch transistor--two junctions separated by a small superconducting island on which the charge can be induced by an external gate voltage. When the Josephson coupling energies of the junctions are equal and...

The magnetic response of three-dimensional Josephson junction networks to constant or slowly varying external magnetic fields is studied. General equations are written for complex networks made of n elementary cubic cells, each cell containing 12 resistively shunted ideal Josephson junctions. The magnetic-flux distribution in the network is calculated numerically as a function of the external m...

We report on the development of a new family of superconducting quantum interference device (SQUID) current sensors based on sub-micron cross-type Josephson tunnel junctions. Their low total junction capacitance permits high usable voltage swings of more than 100 μV and exceptional low noise of the SQUIDs at 4.2 K. Integrated rf-filters as well as high tolerable background fields during cool-do...

We report the first observations of an astronomical object using a superconducting tunnel junction (STJ) device, a pixel detector with intrinsic energy resolution in the optical wavelength range. The Crab pulsar was observed using a 6 × 6 array of Tantalum STJs at the 4.2-m William Herschel Telescope on La Palma. Each array element provides photon counting capability recording up to ∼ 10 3 phot...

We have successfully employed the recently observed quasiparticle admittance of a superconducting tunnel junction as the tuning element for a superconductorinsulator-superconductor mixer. This is the first demonstration of an electronic on-chip tuning element for a superconducting detector. We observe an increase in the dynamic resistance and an improvement in mixer gain and noise temperature a...

We investigate theoretically the Josephson current through one semiconductor quantum dot (QD) coupled to triple nanowires (junctions) with Majorana bound states (MBSs) prepared at their ends. find that not only strength but also period of flowing between left and right junctions via can be fully controlled in terms third junction side-coupled QD. When phase factor is zero junction, which acts a...

We report the first observations of an astronomical object using a superconducting tunnel junction (STJ) device, a pixel detector with intrinsic energy resolution in the optical wavelength range. The Crab pulsar was observed using a 6 × 6 array of Tantalum STJs at the 4.2-m William Herschel Telescope on La Palma. Each array element provides photon counting capability recording up to ∼ 10 3 phot...