Josephson junctions (JJs), where both time-reversal and inversion symmetry are broken, exhibit a phase shift $\phi_0$ in their current-phase relation. This allows for an anomalous supercurrent to flow the junction even absence of bias between superconductors. We show that finite also manifests so-called Andreev interferometers - device consists mesoscopic conductor coupled $\phi_0$-junction. Du...

We develop a theory for the quantum circuit consisting of a superconducting loop interrupted by four Josephson junctions and pierced by a magnetic flux (either static or time-dependent). In addition to the similarity with the typical three-junction flux qubit in the double-well regime, we demonstrate the difference of the four-junction circuit from its three-junction analogue, including its adv...

2014 Two new types of superconducting infrared bolometer are described. In one, the temperature dependent Josephson current in an SNS junction is measured with a SQUID galvanometer. In the other, the temperature-dependent quasiparticle tunneling current in an SIN junction is measured with a conventional fet amplifier. Either type of junction is deposited on a low heat capacity sapphire substrat...

We propose and theoretically investigate superconducting spin qubits. Superconducting spin qubit consists of a single spin confined in a Josephson junction. We show that owing to spin-orbit interaction, superconducting phase difference across the junction can polarize this spin. We demonstrate that this enables single-qubit operations and more complicated quantum gates, where spins of different...

Emission of terahertz (THz) electromagnetic (EM) waves from a high critical temperature (Tc) superconductor intrinsic Josephson junction (IJJ) is a new and promising candidate for practical applications of superconducting devices. From the engineering viewpoint, the IJJ THz source is competitive against the present semiconducting THz sources such as quantum cascade lasers (QCLs) and resonance t...

We outline a number of high temperature superconducting Josephson junction-based devices including superconducting quantum interference devices (SQUIDs) developed for a wide range of applications including geophysical exploration, magnetic anomaly detection, terahertz (THz) imaging and microwave communications. All these devices are based on our patented technology for fabricating YBCO step-edg...

Circulators and directional amplifiers are crucial nonreciprocal signal routing and processing components involved in microwave read-out chains for a variety of applications. They are particularly important in the field of superconducting quantum information, where the devices also need to have minimal photon losses to preserve the quantum coherence of signals. Conventional commercial implement...

We analyze the coupling of two flux qubits with a general many-body projector into low-energy subspace. Specifically, we extract effective Hamiltonians that controls dynamics when they are coupled via capacitor and/or Josephson junction. While induces static charge tunable by design, junction produces magnetic-like interaction easily replacing superconducting quantum interference device. Those ...