Ubiquitous Non-Majorana Zero-Bias Conductance Peaks in Nanowire Devices

J Chen (1) , B D Woods (2) , P Yu (1) , M. Hocevar (3) , D. Car (4) , S.R. Plissard (5) , E. Bakkers (4) , T D Stanescu (2) , S M Frolov (1)

1 Department of Physics and Astronomy [Pittsburgh]
2 West Virginia University [Morgantown]
3 NEEL - NPSC - Nanophysique et Semiconducteurs
4 TU/e - Eindhoven University of Technology [Eindhoven]
5 LAAS-MPN - Équipe Matériaux et Procédés pour la Nanoélectronique

We perform tunneling measurements on indium antimonide nanowire-superconductor hybrid devices fabricated for the studies of Majorana bound states. At finite magnetic field, resonances that strongly resemble Majorana bound states, including zero-bias pinning, become common to the point of ubiquity. Since Majorana bound states are predicted in only a limited parameter range in nanowire devices, we seek an alternative explanation for the observed zero-bias peaks. With the help of a self-consistent Poission-Schrödinger multiband model developed in parallel, we identify several families of trivial subgap states that overlap and interact, giving rise to a crowded spectrum near zero energy and zero-bias conductance peaks in experiments. These findings advance the search for Majorana bound states through improved understanding of broader phenomena found in superconductor-semiconductor systems.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Physique Quantique [quant-ph]; Cristallographie; Matériaux

J Chen, B D Woods, P Yu, M. Hocevar, D. Car, et al.. Ubiquitous Non-Majorana Zero-Bias Conductance Peaks in Nanowire Devices. Physical Review Letters, 2019, 123 (10), pp.107703. ⟨10.1103/PhysRevLett.123.107703⟩. ⟨hal-02332243⟩