Supercurrent-induced topological phase transitions

We will present our recent results showing that finite current in superconductors can induce topological phase transitions, as a result of the deformation of the quasiparticle spectrum by a finite center-of-mass (COM) momentum of the Cooper pairs [1]. To show the wide applicability of this mechanism, we examine the topological properties of three prototypical systems, the Kitaev chain, s-wave superconductors, and d-wave superconductors. We introduce a finite COM momentum as an external field corresponding to supercurrent and show that all the models exhibit current-induced topological phase transitions. We will also address the possibility of observing the phase transitions in experiments and the relation to the other finite COM momentum pairing states. If time allows, we would like to mention our more recent works [2] and ongoing studies.

[1] KT, S. Sumita, Y. Yanase, Phys. Rev. B 106, 014508 (2022).

[2] S. Sumita, KT, J. Phs. Soc. Jpn. 91, 074703 (2022).