Distinguishing Majorana bound states from localized Andreev bound states by interferometry

Up to now, transport spectroscopy of superconducting islands with strong spin-orbit coupling has revealed a robust zero-bias peak in various setups upon applying a magnetic field. While this observation is consistent with the formation of topologically nontrivial Majorana bound states, a careful distinction from topologically trivial Andreev bound states is a vital step. Here, the authors show that two-terminal Andreev bound states can be distinguished from two-terminal Majorana bound states by an interference experiment. Such experiments can be implemented by using current fabrication capabilities and may also be useful to probe quasiparticle poisoning rates for nonisolated islands.