Andreev bound states in junctions formed by conventional and $\mathcal{PT}$-symmetric non-Hermitian superconductors

Abstract

We study theoretically a junction of a $\mathcal{PT}$-symmetric non-Hermitian superconductor (PTS) placed between two conventional superconductors. We show that due to non-Hermitian electron-electron interaction in the PTS region and the combination of symmetries, only discrete values of phases of the conventional superconductors yield solutions for Andreev bound states. Remarkably, in the case of $0$ and $\pi$, we obtain growing and decaying in time Andreev bound states. For $\pi/2$ and $3\pi/2$, there is a Majorana zero mode penetrating through the junction in only one direction forming a quasiparticle supercurrent.