Antiferromagnetic Topological Superconductor and Electrically Controllable Majorana Fermions

TL;DR

This paper proposes a method to realize and control Majorana fermions in a buckled honeycomb system with superconductivity, using electric fields to induce topological phases and manipulate Majorana modes for potential quantum computing applications.

Contribution

It introduces a new approach to create and electrically control Majorana fermions in a honeycomb system with superconductivity, highlighting the role of electric fields in topological phase transitions.

Findings

Majorana modes appear at phase boundaries in the system.

Electric fields can induce topological phases in the honeycomb system.

Majorana fermions can be moved arbitrarily using electric field spots.

Abstract

We investigate the realization of a topological superconductor in a generic bucked honeycomb system equipped with four types of mass-generating terms, where the superconductor gap is introduced by attaching the honeycomb system to an $s$-wave superconductor. Constructing the topological phase diagram, we show that Majorana modes are formed in the phase boundary. In particular, we analyze the honeycomb system with antiferromagnetic order in the presence of perpendicular electric field $E_{z}$. It becomes topological for $|E_{z}|>E_{z}^{\text{cr}}$ and trivial for $|E_{z}|<E_{z}^{\text{cr}}$, with $E_{z}^{\text{cr}}$ a certain critical field. It is possible to create a topological spot in a trivial superconductor by controlling applied electric field. One Majorana zero-energy bound state appears at the phase boundary. We can arbitrarily control the position of the Majorana fermion by moving the spot of applied electric field, which will be made possible by a scanning tunneling microscope probe.