Topological Josephson vortices at finite voltage bias

TL;DR

This paper investigates how finite voltage bias influences vortex states in topological Josephson junctions, revealing a dynamical transition where states collapse and a unique interplay between vortex motion and quantum coherence emerges.

Contribution

It introduces a detailed analysis of voltage-driven vortex dynamics and their impact on Caroli-de Gennes-Matricon states in topological Josephson junctions, highlighting a new dynamical transition.

Findings

Vortices are driven into steady motion by finite voltage bias.

A critical voltage causes CdGM states to collapse to zero energy.

Time-averaged current vanishes in the steady-state regime.

Abstract

We study the effects of finite voltage bias on Caroli-de Gennes-Matricon (CdGM) states in topological Josephson junctions with a vortex lattice. The voltage drives vortices into steady motion, squeezing the CdGM spectrum due to quasi-relativistic dispersion. A finite voltage range allows well-defined states, but beyond a critical breakdown voltage, the states collapse to zero energy and become sharply localized, marking a dynamical transition. Additionally, finite bias modifies selection rules for CdGM state transitions. Notably, in the steady-state regime, the time-averaged current vanishes, revealing a novel interplay between vortex dynamics and quantum coherence.