The superconducting diode effect refers to an asymmetry in the critical supercurrent Jc(n^) along opposite directions, Jc(n^)=Jc(−n^). While the basic symmetry requirements for this effect are known, it is, for junction-free systems, difficult to capture within current theoretical models the large current asymmetries Jc(n^)/Jc(−n^) recently observed in experiment. We here propose and develop a theory for an enhancement mechanism of the diode effect arising from spontaneous symmetry breaking. We show - both within a phenomenological and a microscopic theory - that there is a coupling of the supercurrent and the underlying symmetry-breaking order parameter. This coupling can enhance the current asymmetry significantly. Our work might not only provide a possible explanation for recent experiments on trilayer graphene but also pave the way for future realizations of the superconducting diode effect with large current asymmetries.
@article{arxiv.2304.03303,
title = {Enhanced Superconducting Diode Effect due to coexisting Phases},
author = {Sayan Banerjee and Mathias S. Scheurer},
journal= {arXiv preprint arXiv:2304.03303},
year = {2024}
}