Transport spectroscopy for Paschen-Back splitting of Landau levels in InAs nanowires

TL;DR

This paper reports the first observation of Paschen-Back splitting of Landau levels in InAs nanowires under strong magnetic fields, revealing LL-dependent anomalous Zeeman effects linked to spin-orbit coupling, with implications for spin-resolved transport.

Contribution

It provides the first experimental demonstration of PB splitting in solid-state nanowires and connects it with Rashba SOC theory, advancing understanding of spin effects in nanostructures.

Findings

Observation of LL-dependent anomalous Zeeman splitting

Good agreement with Rashba SOC theoretical analysis

Potential for generating spin-resolved electron transport

Abstract

The coupling of electron orbital motion and spin leads to nontrivial changes in energy-level structures, leading to various spectroscopies and applications. In atoms, such spin-orbit coupling (SOC) causes anomalous Zeeman splitting, known as the Paschen-Back (PB) effect, in the pres-ence of a strong magnetic field. In solids, SOC generates energy-band inversion or splitting, a prerequisite for topological phases or Majorana fermions, at zero or weak magnetic fields. Here, we present the first observation of PB splitting of Landau levels (LLs) in indium arsenide nan-owires in a strong-field regime. Our energy-resolved transport spectroscopy results indicated the presence of LL-dependent anomalous Zeeman splitting in these nanowires, analogous to the atomic PB effect. This result was found to be in good agreement with a theoretical analysis based on Rashba SOC. Our findings also suggested a way of generating spin-resolved electron transport in nanowires.