Multiple phase slips phenomena in mesoscopic superconducting rings

TL;DR

This paper studies the dynamics of phase slips in mesoscopic superconducting rings using simulations of Ginzburg-Landau equations, revealing conditions for stability and the influence of characteristic times and noise.

Contribution

It provides a detailed analysis of multiple phase slip phenomena, including stability conditions and the role of the ratio of characteristic times u, based on analytical and simulation results.

Findings

Consecutive phase slips are favored when u>>1.

Simultaneous phase slips occur when u<<1.

Noise influences the phase transition kinetics.

Abstract

We investigate the behavior of a mesoscopic one-dimensional ring in an external magnetic field by simulating the time dependent Ginzburg-Landau equations with periodic boundary conditions. We analyze the stability and the different possible evolutions for the phase slip phenomena starting from a metastable state. We find a stability condition relating the winding number of the initial solution and the number of flux quanta penetrating the ring. The analysis of multiple phase slips solutions is based on analytical results and simulations. The role of the ratio of two characteristic times u is studied for the case of a multiple phase slips transition. We found out that if u>>1, consecutive multiple phase slips will be more favorable than simultaneous ones. If u<<1 the opposite is true and we confirm that u>>1 is often a necessary condition to reach the ground state. The influence of the Langevin noise on the kinetics of the phase transition is discussed.