Spin-Resolved Magneto-Tunneling and Giant Anisotropic <i>g</i>-Factor in Broken Gap InAs-GaSb Core-Shell Nanowires.

Clericò, Vito; Wójcik, Pawel; Vezzosi, Andrea; Rocci, Mirko; Demontis, Valeria; Zannier, Valentina; Díaz-Fernández, Álvaro; Díaz, Elena et al. · Nano Lett · 2024

basic_science · Level V

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Abstract

We experimentally and computationally investigate the magneto-conductance across the radial heterojunction of InAs-GaSb core-shell nanowires under a magnetic field, <i>B</i>, up to 30 T and at temperatures in the range 4.2-200 K. The observed double-peak negative differential conductance markedly blue-shifts with increasing <i>B</i>. The doublet accounts for spin-polarized currents through the Zeeman split channels of the InAs (GaSb) conduction (valence) band and exhibits strong anisotropy with respect to <i>B</i> orientation and marked temperature dependence. Envelope function approximation and a semiclassical (WKB) approach allow to compute the magnetic quantum states of InAs and GaSb sections of the nanowire and to estimate the <i>B</i>-dependent tunneling current across the broken-gap interface. Disentangling different magneto-transport channels and a thermally activated valence-to-valence band transport current, we extract the <i>g</i>-factor from the spin-up and spin-down d<i>I</i>/d<i>V</i> branch dispersion, revealing a giant, strongly anisotropic <i>g</i>-factor in excess of 60 (100) for the radial (tilted) field configurations.