Probing non-Abelian statistics with Majorana fermion interferometry in spin-orbit-coupled semiconductors

The list of quantum-mechanical systems with non-Abelian statistics has recently been expanded by including generic spin-orbit-coupled semiconductors (e. g., InAs) in proximity to an s-wave superconductor. Demonstration of the anyonic statistics using Majorana fermion interferometry in this system is a necessary first step toward topological quantum computation (TQC). However, since all isolated chiral edges that can be created in the semiconductor are charge neutral, it is not clear if electrically controlled interferometry is possible in this system. Here we show that when two isolated chiral Majorana edges are brought into close contact, the resultant interface supports charge current, enabling electrically controlled Majorana fermion interferometry in the semiconductor structure. Such interferometry experiments on the semiconductor are analogous to similar interferometry experiments on the v = 5/2 fractional quantum Hall systems and on the surface of a three-dimensional (3D) strong topological insulator, illustrating the usefulness of the 2D semiconductor heterostructure as a suitable TQC platform. In particular, we propose thatMajorana interferometers may be the most direct method for establishing non-Abelian braiding statistics in topological superconductors.