Signatures of exceptional points in multiterminal superconductor-normal metal junctions

Abstract

We study a non-Hermitian, multiterminal superconducting-normal system in order to identify experimental signatures of exceptional points. We focus on a minimal setting with a single spinful level, spin-dependent normal leads, and a noncollinear magnetic field. This system hosts both topologically-protected, as well as symmetry-protected exceptional points. Using an exact transport formalism, we show that the exceptional points leave signatures visible through spectroscopy of the Andreev states, but that they have a minor effect on the Josephson current. We also argue that these findings hold with interactions.