Interaction Driven Floquet Engineering of Topological Superconductivity in Rashba Nanowires

We analyze, analytically and numerically, a periodically driven Rashba nanowire proximity coupled to an s-wave superconductor [1] using bosonization and renormalization group analysis in the regime of strong electron-electron interactions. Due to the repulsive interactions, the superconducting gap is suppressed, whereas the Floquet Zeeman gap is enhanced, resulting in a higher effective value of g-factor compared to the non-interacting case [2]. The flow equations for different coupling constants, velocities, and Luttinger-liquid parameters explicitly establish that even for small initial values of the Floquet Zeeman gap compared to the superconducting proximity gap, the interactions drive the system into the topological phase and the interband interaction term helps to achieve larger regions of the topological phase in parameter space.

[1] M. Thakurathi et al, Phys. Rev. B 95, 155407 (2017).
[2] M. Thakurathi et al, arXiv:1910.03730.