Closing the proximity gap in a metallic Josephson junction between three superconductors

We describe the proximity effect in a short disordered metallic junction between three superconducting leads. Andreev bound states in the multiterminal junction may cross the Fermi level. We reveal that for a quasicontinuous metallic density of states, crossings at the Fermi level manifest as a closing of the proximity-induced gap. We calculate...

Effect of mechanical resonance on Josephson dynamics

We study theoretically dynamics in a Josephson junction coupled to a mechanical resonator looking at the signatures of the resonance in dc electrical response of the junction. Such a system can be realized experimentally as a suspended ultraclean carbon nanotube brought in contact with two superconducting leads. A nearby gate electrode can be...

Statistics of radiation at Josephson parametric resonance

Motivated by recent experiments, we study theoretically the full counting statistics of radiation emitted below the threshold of parametric resonance in a Josephson-junction circuit. In contrast to most optical systems, a significant part of emitted radiation can be collected and converted to an output signal. This permits studying the...

Theoretical proposal for superconducting spin qubits

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...