Longitudinal and transverse noise in a moving Vortex Lattice

TL;DR

This study investigates the velocity fluctuations in a moving vortex lattice, revealing that both longitudinal and transverse components have similar broad spectra and are unaffected by velocity or small perturbations, indicating a noisy surface current flow.

Contribution

It provides new insights into vortex lattice dynamics by showing the isotropic nature of velocity fluctuations and the absence of bulk averaging or crystallization effects.

Findings

Longitudinal and transverse velocity fluctuations are similar in spectrum and magnitude.

Velocity fluctuations are insensitive to changes in velocity and small perturbations.

Results support a model of noisy surface current flow with isotropic elementary fluctuators.

Abstract

We have studied the longitudinal and the transverse velocity fluctuations of a moving vortex lattice (VL) driven by a transport current. They exhibit both the same broad spectrum and the same order of magnitude. These two components are insensitive to the velocity and to a small bulk perturbation. This means that no bulk averaging over the disorder and no VL crystallization are observed. This is consistently explained referring to a previously proposed noisy flow of surface current whose elementary fluctuator is measured isotropic.