A study of supercooling of the disordered vortex phase via minor hysteresis loops in 2H-NbSe_2

TL;DR

This paper investigates the supercooling of disordered vortex phases in NbSe_2 using minor hysteresis loops, revealing differences in flux line lattice order depending on field history and providing insights into vortex phase transitions.

Contribution

It introduces a novel interpretation of minor hysteresis loops to study supercooling and vortex phase behavior in NbSe_2, highlighting the role of field history in vortex lattice order.

Findings

Supercooling of disordered vortex phase observed during field cooling.

Differences in flux lattice order between ascending and descending fields.

Spatial order in flux line lattice depends on field history and annealing.

Abstract

We report on the observation of novel features in the minor hysteresis loops in a clean crystal of NbSe_2 which displays a peak effect. The observed behavior can be explained in terms of a supercooling of the disordered vortex phase while cooling the superconductor in a field. Also, the extent of spatial order in a flux line lattice formed in ascending fields is different from (and larger than) that in the descending fields below the peak position of the peak effect; this is attributed to unequal degree of annealing of the state induced by a change of field in the two cases.