P. T. How | Searcharxiv

arXiv2024

Broken time reversal symmetry vestigial state for a two-component superconductor in two spatial dimensions

We consider the vestigial phase with broken time-reversal symmetry above the superconducting transition temperature of a two-component superconductor in two spatial dimensions. We show that, in contrast to 3D, a vestigial phase is in general allowed within Ginzburg-Landau theory. The vestigial phase occupies an increasing temperature region if the parameters in the Ginzburg-Landau theory gives a larger energy difference between the broken time reversal symmetry phase and the other ordered phase.

cond-mat.supr-con↗

arXiv2022

Criterion for Vestigial Order above a Nematic Superconductor

A nematic superconductor can in principle support a vestigial order phase above its superconducting transition temperature, with rotational symmetry spontaneously broken while remain nonsuperconducting. We examine the condition for this vestigial nematic order to occur, within a Ginzburg-Landau theory with order parameter fluctuations included. Contrary to prior theoretical results, we found that this vestigial order actually requires very stringent conditions to be met: the material must be sufficiently deep in the nematic regime (i.e. far away from the boundary separating the nematic and chiral superconducting phases) to possibly exhibit a vestigial nematic order.

cond-mat.supr-con↗