Superconducting proximity effect and Majorana fermions at the surface of a topological insulator

TL;DR

This paper explores how the proximity effect induces a topological superconducting state on a topological insulator surface, enabling the creation and manipulation of Majorana fermions for potential quantum computing applications.

Contribution

It demonstrates the formation of a non-chiral 1D Majorana wire via superconductor-topological insulator junctions and proposes circuits for Majorana state control.

Findings

Majorana bound states can exist at vortices in the induced superconducting state.

Linear junctions act as Majorana fermion wires.

Proposed circuits enable Majorana state manipulation.

Abstract

We study the proximity effect between an s-wave superconductor and the surface states of a strong topological insulator. The resulting two dimensional state resembles a spinless p_x+ip_y superconductor, but does not break time reversal symmetry. This state supports Majorana bound states at vortices. We show that linear junctions between superconductors mediated by the topological insulator form a non chiral 1 dimensional wire for Majorana fermions, and that circuits formed from these junctions provide a method for creating, manipulating and fusing Majorana bound states.