Two-dimensional platform for networks of Majorana bound states

Michael Hell, Martin Leijnse, Karsten Flensberg

Published 2016-08-31Version 1

We model theoretically a two-dimensional electron gas (2DEG) covered by a superconductor and demonstrate that topological superconducting channels are formed when stripes of the superconducting layer are removed. As a consequence, Majorana bound states (MBS) are created at the ends of the stripes. We calculate the topological invariant and energy gap of a single stripe, using realistic values for an InAs 2DEG proximitized by an epitaxial Al layer. We show that the topological gap is enhanced by introducing an asymmetry in the stripe, which can be achieved by either a phase bias or by an asymmetric gate design. Both strategies also enable electrical control over the MBS splitting, thereby facilitating braiding and readout schemes based on controlled fusion of MBS. Finally, we outline how a network of Majorana stripes can be designed.