# Metastability and hysteretic vortex pinning near the order-disorder transition in NbSe$_2$: An interplay between plastic and elastic energy barriers?

## TL;DR

This study investigates the complex interplay of elastic and plastic energy barriers affecting vortex lattice metastability and hysteresis near the order-disorder transition in NbSe₂, revealing how thermal and dynamic history influence vortex pinning.

## Contribution

It introduces a novel scenario explaining vortex metastability and hysteresis through the interplay of elastic and plastic energy barriers in NbSe₂.

## Key findings

- Metastable vortex lattice configurations coexist with hysteretic pinning.
- Plastic barriers require dynamic assistance to overcome, affecting vortex stability.
- Thermal hysteresis is linked to low energy barriers inhibiting vortex rearrangement.

## Abstract

We studied thermal and dynamic history effects in the vortex lattice (VL) near the order-disorder transition in clean NbSe$_2$ single crystals. Comparing the evolution of the effective vortex pinning and the bulk VL structure, we observed metastable superheated and supercooled VL configurations that coexist with a hysteretic effective pinning response due to thermal cycling of the system. A novel scenario, governed by the interplay between (lower) elastic and (higher) plastic energy barriers, is proposed as an explanation for our observations: Plastic barriers, which prevent the annihilation or creation of topological defects, require dynamic assistance to be overcome and to achieve a stable VL at each temperature. Conversely, thermal hysteresis in the pining response is ascribed to low energy barriers, which inhibit rearrangement within a single VL correlation volume and are easily overcome as the relative strength of competing interactions changes with temperature.