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

摘要

We study the Zeeman splitting in lateral quantum dots that are defined inGaAs-AlGaAs het- erostructures by means of split gates. We demonstrate anon-linear dependence of the splitting on magnetic field and its substantialvariations from dot to dot and from heterostructure to het- erostructure. Thesephenomena are important in the context of information processing since thetunability and dot-dependence of the Zeeman splitting allow for a selectivemanipulation of spins. We show that spin-orbit effects related to the GaAs bandstructure quantitatively explain the ob- served magnitude of the non-lineardependence of the Zeeman splitting. Furthermore, spin-orbit effects result in adependence of the Zeeman splitting on predominantly the out-of-plane quantumdot confinement energy. We also show that the variations of the confinementenergy due to charge disorder in the heterostructure may explain the dependenceof Zeeman splitting on the dot position. This position may be varied bychanging the gate voltages which leads to an electrically tunable Zeemansplitting.