Driven weak to strong pinning crossover in partially nanopatterned 2H-NbSe2 single crystal

TL;DR

This study explores how partial nanopatterning in 2H-NbSe2 single crystals causes an unconventional transition from weak to strong vortex pinning, influenced by drive and magnetic field, affecting vortex dynamics.

Contribution

It uncovers a novel dynamic weak to strong pinning crossover in nanopatterned 2H-NbSe2, showing drive-dependent magnetization responses and vortex flow hindrance.

Findings

Magnetization response is drive-dependent and non-monotonic.

Pinning force increases with drive even when all centers are saturated.

Vortex flow can be hindered or jammed at higher drives.

Abstract

Investigations into the heterogeneous pinning properties of the vortex state created by partially nano-patterning single crystals of 2H-NbSe2 reveal an atypical magnetization response which is significantly drive dependent. Analysis of the magnetization response shows non-monotonic behavior of the magnetization relaxation rate with varying magnetic field sweep rate. With all the patterned pinning centers saturated with vortices, we find that the pinning force experienced by the vortices continues to increase with increasing drive. Our studies reveal an unconventional dynamic weak to strong pinning crossover where the flow of the vortex state appears to be hindered or jammed as it is driven harder through the interstitial voids in the patterned pinning lattice.