Non-linear and dot-dependent Zeeman splitting in GaAs/AlGaAs quantum dot arrays

TL;DR

This paper investigates the non-linear and dot-dependent Zeeman splitting in GaAs/AlGaAs quantum dot arrays, revealing how spin-orbit effects and charge disorder influence spin manipulation for quantum information processing.

Contribution

It demonstrates the role of spin-orbit interactions and charge disorder in causing non-linear and position-dependent Zeeman splitting in quantum dots.

Findings

Non-linear Zeeman splitting observed in quantum dots.

Spin-orbit effects quantitatively explain the splitting behavior.

Charge disorder influences dot-to-dot variations and tunability.

Abstract

We study the Zeeman splitting in lateral quantum dots that are defined in GaAs-AlGaAs het- erostructures by means of split gates. We demonstrate a non-linear dependence of the splitting on magnetic field and its substantial variations from dot to dot and from heterostructure to het- erostructure. These phenomena are important in the context of information processing since the tunability and dot-dependence of the Zeeman splitting allow for a selective manipulation of spins. We show that spin-orbit effects related to the GaAs band structure quantitatively explain the ob- served magnitude of the non-linear dependence of the Zeeman splitting. Furthermore, spin-orbit effects result in a dependence of the Zeeman splitting on predominantly the out-of-plane quantum dot confinement energy. We also show that the variations of the confinement energy due to charge disorder in the heterostructure may explain the dependence of Zeeman splitting on the dot position. This position may be varied by changing the gate voltages which leads to an electrically tunable Zeeman splitting.