Giant low frequency velocity fluctuations in a driven vortex lattice

TL;DR

This paper investigates large, low-frequency velocity fluctuations in a driven vortex lattice in 2H-NbSe2, revealing a regime of coherent dynamics with unexpected fluctuation behavior prior to the peak effect.

Contribution

It uncovers a previously unexplored regime of coherent vortex lattice dynamics and characterizes large velocity fluctuations in a driven flux line lattice.

Findings

Substantial low-frequency velocity fluctuations observed (~ seconds)

Fluctuations are affected by a superimposed periodic drive

Identification of a new regime of coherent vortex dynamics before peak effect

Abstract

The driven state of a well-ordered flux line lattice in a single crystal of 2H-NbSe2 in the time domain has revealed the presence of substantial fluctuations in velocity, with large and distinct time periods (~ seconds). A superposition of a periodic drive in the driven vortex lattice causes distinct changes in these fluctuations. We propose that prior to onset of the peak effect there exist hithertofore unexplored regime of coherent dynamics, with unexpected behaviour in velocity fluctuations.