Realization of a Josephson Switch

TL;DR

This paper explores a practical Josephson junction switch that can control supercurrent flow using magnetic fields, with potential applications in realizing time crystals and similar phenomena.

Contribution

It provides a detailed analysis of a Josephson switch mechanism and proposes a parallel superfluid system, advancing experimental approaches to time crystal realization.

Findings

Magnetic field can effectively switch supercurrent on and off.

Tuning parameters allows near-equilibrium free energy without reducing lifetime.

Parallel superfluid system proposed for similar switching behavior.

Abstract

It has been proposed that intermittent weak links between spontaneously broken symmetry systems can give rise to a novel type of time crystal. Here a practical construction is analyzed in greater detail. For a film-geometry Josephson junction, an applied magnetic field in the junction region can effectively switch on and off the supercurrent. By tuning experimental parameters, one can possibly let the free energy be arbitrarily close to the equilibrium without compromising the life time. A parallel construction for superfluid $^4$He is also proposed.