Supercooling across first-order phase transitions in vortex matter

TL;DR

This paper investigates hysteresis and supercooling phenomena in vortex matter during first-order phase transitions, emphasizing how the metastable region depends on the path taken in temperature and magnetic field space.

Contribution

It introduces the concept that the observable metastable region in vortex matter depends on the path in H-T space, especially contrasting temperature and magnetic field variations.

Findings

Metastability region depends on the path in H-T space.

Supercooled phase stability varies with temperature and magnetic field changes.

Path dependence of metastability is distinct from kinetic hindrance effects.

Abstract

Hysteresis in cycling through first-order phase transitions in vortex matter, akin to the well-studied phenomenon of supercooling of water, has been discussed in literature. Hysteresis can be seen while varying either temperature T or magnetic field H (and thus the density of vortices). Our recent work on phase transitions with two control variables shows that the observable region of metastability of the supercooled phase would depend on the path followed in H-T space, and will be larger when T is lowered at constant H compared to the case when H is lowered at constant T. We discuss the effect of isothermal field variations on metastable supercooled states produced by field-cooling. This path dependence is not a priori applicable to metastability caused by reduced diffusivity or hindered kinetics.