Polarization dependent Landau level crossing in a two-dimensional electron system in MgZnO/ZnO-heterostructure

TL;DR

This study investigates how spin-resolved Landau levels cross in a high-mobility MgZnO/ZnO 2D electron system under tilted magnetic fields, revealing spin susceptibility behavior and level crossing shifts.

Contribution

It provides new insights into Landau level crossings and spin susceptibility in MgZnO/ZnO heterostructures under tilted magnetic fields.

Findings

Multiple Landau level crossing events observed.

Spin susceptibility shows deviation from Pauli behavior.

Landau level crossing shifts to smaller tilt angles.

Abstract

We report electrical transport measurements in a tilted magnetic field on a high-mobility two-dimensional electron system confined at the MgZnO/ZnO heterointerface. The observation of multiple crossing events of spin-resolved Landau levels (LLs) enables the mapping of the sequence of electronic states. We further measure the renormalization of electron spin susceptibility at zero field and the susceptibility dependence on the electron spin polarization. The latter manifests the deviation from the Pauli spin susceptibility. As the result, the crossing of spin-resolved LLs shifts to smaller tilt angles and the first Landau level coincidence event is absent even when the magnetic field has only a perpendicular component to the 2DES plane.