Fulde-Ferrell-Larkin-Ovchinnikov phases in Proximitized Josephson junctions

Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phases, which are notoriously difficult to find in more homogeneous systems, have been observed in proximitized superconductors. Of particular interest are those heterostructures which are associated with topological phases[1,2]. In this talk, we establish the effects of spin-orbit coupling and show why these elusive phases are observable in the presence of proximitization. We focus on that FFLO phase which appears inside a substrate (subjected to an in-plane magnetic field) and formed in a Josephson junction configuration. To do so, we solve the Bogoliubov-de Gennes equations for the full multi-component system. The substrates consist of (1) a conical Holmium magnet with an effective 1D spin-orbit coupling, and (2) a two-dimensional electron gas.

[1] Hart et al., Nat Phys. 13, 87 (2017).
[2] Chen et al, Nat Comm 9, 2478 (2018)