Diode effect in bilayer superconductors in a magnetic field

Superconducting diode effect, or the phenomenon of unequal supercurrents in opposite directions may play a major role in fabricating quantum devices. It has been shown experimentally that the breaking of time reversal symmetry (using external magnetic field) and the inversion symmetry of the superconductor can give rise to the phenomenon¹. We have obtained the phase diagram of coupled bilayer superconductors with an in-plane magnetic field and showed that for some parameters it supports a stripe phase of alternating BCS phases separated by inter-layer vortices². In the present work, we solve self-consistent gap equations in the presence of a current to show that this system also displays the diode effect. We further investigate how the diode effect is affected by the formation of stripes.

1. Hou, Y., Nichele, F., Chi, H., Lodesani, A., Wu, Y., Ritter, M. F., Haxell, D. Z., Davydova, M., Ilić, S., Glezakou-Elbert, O., Varambally, A., Bergeret, F. S., Kamra, A., Fu, L., Lee, P. A., & Moodera, J. S. (2023). Ubiquitous Superconducting Diode Effect in Superconductor Thin Films. Physical Review Letters, 131(2), 027001. https://doi.org/10.1103/PhysRevLett.131.027001

2. U. Nag, J. Schirmer, E. Rossi, C.-X. Liu, and J. K. Jain, BCS Stripe Phase in Coupled Bilayer Superconductors, http://arxiv.org/abs/2408.00689.