Large Zeeman Splitting in Out-of-Plane Magnetic Field in a Double-Layer Quantum Point Contact

TL;DR

This paper reports a significant Zeeman splitting in a double quantum well quantum point contact under out-of-plane magnetic fields, revealing an enhanced g-factor due to many-body interactions in high mobility, low-density electron systems.

Contribution

It demonstrates a large Zeeman splitting and g-factor enhancement in a double quantum well quantum point contact under perpendicular magnetic field, highlighting strong many-body effects.

Findings

Zeeman energy reaches 0.09 meV at 0.16 T

g-factor is enhanced by 17.5 times

strong many-body interactions observed

Abstract

In this study, we observe that the conductance of a quantum point contact on a GaAs/AlGaAs double quantum well depends significantly on the magnetic field perpendicular to the two-dimensional electron gas. In the presence of the magnetic field, the subband edge splitting due to the Zeeman energy reaches 0.09 meV at 0.16 T, thereby suggesting an enhanced g-factor. The estimated g-factor enhancement is 17.5 times that of the bare value. It is considered that a low electron density and high mobility makes it possible to reach a strong many-body interaction regime in which this type of strong enhancement in g-factor can be observed.