Electrical manipulation of Majorana fermions in an interdigitated superconductor-ferromagnet device

Abstract

We show that a topological phase supporting Majorana fermions can form in a 2D electron gas (2DEG) adjacent to an interdigitated superconductor-ferromagnet structure. An advantage of this setup is that the 2DEG can induce the required Zeeman splitting and superconductivity from a single interface, allowing one to utilize a wide class of 2DEGs including the surface states of bulk InAs. We demonstrate that the interdigitated device supports a robust topological phase when the finger spacing lambda is smaller than half of the Fermi wavelength lambda_F. In this regime, the electrons effectively see a "smeared" Zeeman splitting and pairing field despite the interdigitation. The topological phase survives even in the opposite limit lambda>lambda_F/2, though with a reduced bulk gap. We describe how to electrically generate a vortex in this setup to trap a Majorana mode, and predict an anomalous Fraunhofer pattern that provides a sharp signature of chiral Majorana edge states.

5 pages, 6 figures

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• Detecting Non-Abelian Statistics in the nu=5/2 Fractional Quantum Hall State
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Cited by in corpus (8)

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• Phase-Controllable Nonlocal Spin Polarization in Proximitized Nanowires
• Signatures of superconducting triplet pairing in Ni--Ga-bilayer junctions
• Spin singlet topological superconductivity in the attractive Rashba Hubbard model
• Vertex correction for the linear and nonlinear optical responses in superconductors: multiband effect and topological superconductivity
• Renormalized and iterative formalism of the Andreev levels within large multi-parametric space
• Noise as a probe of Majorana fermion surface states