Long-range Cooper pair splitting by chiral Majorana edge states

Abstract

We analyze the transport properties of a Cooper pair splitter device composed of two-point electrodes in contact with a ferromagnetic/superconductor (F/S) junction constructed on the surface of a topological insulator (TI). For the pair potential in the S region, we consider s- and d-wave symmetries, while for the F region, we focus on a magnetization vector normal to the TI surface. Non-local transport along the F/S interface is mediated by chiral Majorana edge states, with chirality controlled by the polarization of the magnetization vector. We demonstrate that crossed Andreev reflections slowly decays with the separation of the electrodes in standard clean samples. Our system exhibits a maximum Cooper pair-splitting efficiency of 80% for a symmetrical voltage configuration, even in high-temperature superconductor devices.