Zero-Energy Modes from Coalescing Andreev States in a Two-Dimensional Semiconductor-Superconductor Hybrid Platform

H J Suominen; M Kjaergaard; A R Hamilton; J Shabani; C J Palmstrøm; C M Marcus; F Nichele

doi:10.1103/PhysRevLett.119.176805

Zero-Energy Modes from Coalescing Andreev States in a Two-Dimensional Semiconductor-Superconductor Hybrid Platform

Phys Rev Lett. 2017 Oct 27;119(17):176805. doi: 10.1103/PhysRevLett.119.176805. Epub 2017 Oct 26.

Authors

H J Suominen¹, M Kjaergaard¹, A R Hamilton^{1

2}, J Shabani^{3

4}, C J Palmstrøm^{3

5

6}, C M Marcus¹, F Nichele¹

Affiliations

¹ Center for Quantum Devices and Station Q Copenhagen, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark.
² School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia.
³ California NanoSystems Institute, University of California, Santa Barbara, California 93106, USA.
⁴ Center for Quantum Phenomena, Physics Department, New York University, New York 10031, USA.
⁵ Department of Electrical Engineering, University of California, Santa Barbara, California 93106, USA.
⁶ Materials Department, University of California, Santa Barbara, California 93106, USA.

PMID: 29219474
DOI: 10.1103/PhysRevLett.119.176805

Abstract

We investigate zero-bias conductance peaks that arise from coalescing subgap Andreev states, consistent with emerging Majorana zero modes, in hybrid semiconductor-superconductor wires defined in a two-dimensional InAs/Al heterostructure using top-down lithography and gating. The measurements indicate a hard superconducting gap, ballistic tunneling contact, and in-plane critical fields up to 3 T. Top-down lithography allows complex geometries, branched structures, and straightforward scaling to multicomponent devices compared to structures made from assembled nanowires.