Electrodynamics of Fulde-Ferrell-Larkin-Ovchinnikov superconducting state

TL;DR

This paper develops a Ginzburg-Landau theory for the vortex lattice in clean 3D superconductors with a large Maki parameter, revealing unique magnetic field components and superfluid current origins in the FFLO state.

Contribution

It introduces a theoretical framework for understanding vortex lattices in the FFLO state, highlighting the role of paramagnetic effects and predicting new magnetic field configurations.

Findings

Vortex lattice remains triangular as in Abrikosov state

Internal magnetic field has components perpendicular to external field

Superfluid currents mainly from paramagnetic spin interactions

Abstract

We develop the Ginzburg-Landau theory of the vortex lattice in clean isotropic three-dimensional superconductors at large Maki parameter, when inhomogeneous Fulde-Ferrell-Larkin-Ovchinnikov state is favored. We show that diamagnetic superfluid currents mainly come from paramagnetic interaction of electron spins with local magnetic field, and not from kinetic energy response to the external field as usual. We find that the stable vortex lattice keeps its triangular structure as in usual Abrikosov mixed state, while the internal magnetic field acquires components perpendicular to applied magnetic field. Experimental possibilities related to this prediction are discussed.