Anomalous supercurrent from Majorana states in topological insulator Josephson junctions

Abstract

We propose a Josephson junction setup based on a topological insulator (TI)\nthin film to detect Majorana states, which exploits the unique helical and\nextended nature of the TI surface state. When the magnetic flux through the\njunction is close to an integer number of flux quanta, Majorana states, present\non both surfaces of the film, give rise to a narrow peak-dip structure in the\ncurrent- phase relation by hybridizing at the edge of the junction. Moreover,\nthe maximal Majorana-state contribution to Josephson current takes a (nearly)\nuniversal value, approximately equal to the supercurrent capacity of a single\nquantum-channel. These features provide a characteristic signature of Majorana\nstates based entirely on supercurrent.\n