#### Abstract

Among the broad spectrum of systems predicted to exhibit topological superconductivity and Majorana fermions, one-dimensional wires with strong spin-orbit coupling provide one of the most promising experimental candidates. Here we investigate the fate of the topological superconducting phase in such wires when repulsive interactions are present. Using a combination of density matrix renormalization group, bosonization, and Hartree–Fock techniques, we demonstrate that while interactions degrade the bulk gap—consistent with recent results of Gangadharaiah *et al.*—they also greatly expand the parameter range over which the topological phase arises. In particular, we show that with interactions this phase can be accessed over a broader chemical potential window, thereby leading to greater immunity against disorder-induced chemical potential fluctuations in the wire. We also suggest that in certain wires strong interactions may allow Majorana fermions to be generated without requiring a magnetic field.

- Received 4 May 2011

DOI:https://doi.org/10.1103/PhysRevB.84.014503

©2011 American Physical Society

#### Synopsis

#### Majorana states thrive under interactions

###### Published 14 July 2011

Calculations show that Coulomb interactions can play a positive role in the hunt for Majorana fermions.

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