Vortex state in double transition superconductors

TL;DR

This paper investigates the vortex structures and phase transitions in double transition superconductors using a two-component Ginzburg-Landau theory, revealing novel vortex phases and the effects of gradient coupling.

Contribution

It introduces a theoretical analysis of vortex states in double transition superconductors, highlighting the deformation of vortex lattices and the impact of gradient coupling on phase transitions.

Findings

Deformation of vortex lattice from triangular structure.

Possibility of vortex sheet structures.

Transition becomes a crossover at finite fields due to gradient coupling.

Abstract

Novel vortex phase and nature of double transition field are investigated by two-component Ginzburg-Landau theory in a situation where fourfold-twofold symmetric superconducting double transition occurs. The deformation from 60 degree triangular vortex lattice and a possibility of the vortex sheet structure are discussed. In the presence of the gradient coupling, the transition changes to a crossover at finite fields. These characters are important to identify the multiple superconducting phase in PrOs_4_Sb_12.