Quantum phase transition in the Fulde-Ferrell-Larkin-Ovchinnikov states of a two dimensional d-wave superconductor upon increasing the exchange field

TL;DR

This paper investigates quantum phase transitions in a 2D d-wave superconductor under increasing exchange field, revealing transitions from uniform to 1D and 2D FFLO states, with local density of states as potential experimental signatures.

Contribution

It introduces a detailed phase diagram showing transitions between uniform and FFLO states in 2D d-wave superconductors under magnetic fields.

Findings

Existence of quantum phase transitions from uniform to FFLO states

Identification of 1D and 2D FFLO phases

Proposed local density of states signatures for phase identification

Abstract

We studied the phase diagram for a two-dimensional d-wave superconducting system under an in-plane magnetic field or an exchange field. According to the spatial configuration of the order parameter, we show that there exists quantum phase transitions in which the uniform phase transforms to the one-dimensional Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, and then to two-dimensional FFLO state upon increasing the exchange field. The local density of states are calculated and suggested to be signatures to distinguish these phases.