FisMat2017 - Submission - View

Abstract's title: Signatures of interaction-induced helical gaps in nanowire quantum point contacts
Submitting author: Niccolò Traverso Ziani
Affiliation: Universitaet Wuerzburg
Affiliation Address: neubaustrasse 64a
Country: Germany
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: S Heedt (Peter Gr¨unberg Institut (PGI-9) and JARA-Fundamentals of Future Information Technology, Forschungszentrum J¨ulich, 52425 J¨ulich, Germany), F Crépin (Laboratoire de Physique Th´eorique de la Mati`ere Condens´ee, UPMC, CNRS UMR 7600, Sorbonne Universit´es, 4 place Jussieu, 75252 Paris Cedex 05, France), W Prost (Solid State Electronics Department, University of Duisburg-Essen, 47057 Duisburg, Germany), St. Trellenkamp(Peter Gr¨unberg Institut (PGI-9) and JARA-Fundamentals of Future Information Technology, Forschungszentrum J¨ulich, 52425 J¨ulich, Germany) J Schubert (Peter Gr¨unberg Institut (PGI-9) and JARA-Fundamentals of Future Information Technology, Forschungszentrum J¨ulich, 52425 J¨ulich, Germany), D Grützmacher (1Peter Gr¨unberg Institut (PGI-9) and JARA-Fundamentals of Future Information Technology, Forschungszentrum J¨ulich, 52425 J¨ulich, Germany), B Trauzettel ( Institute of Theoretical Physics and Astrophysics, University of W¨urzburg, 97074 W¨urzburg, Germany), Th Schäpers (Peter Gr¨unberg Institut (PGI-9) and JARA-Fundamentals of Future Information Technology, Forschungszentrum J¨ulich, 52425 J¨ulich, Germany)
Abstract

Spin-momentum locking in a semiconductor device with strong spin-orbit coupling (SOC) is a fundamental goal of nanoscale spintronics and an important prerequisite for the formation of Majorana bound states . Such a helical state is predicted in one-dimensional (1D) nanowires subject to strong Rashba SOC and spin-mixing, its hallmark being a characteristic reentrant behaviour in the conductance. Here, we report the first direct experimental observations of the reentrant conductance feature, which reveals the formation of a helical liquid, in the lowest 1D subband of an InAs nanowire. Surprisingly, the feature is very prominent also in the absence of magnetic fields. This behaviour suggests that exchange interaction exhibits substantial impact on transport in our device. We attribute the opening of the pseudogap to spin-flipping two-particle backscattering. The all-electric origin of the ideal helical transport bears momentous implications for topological quantum computing.