Proposal of Spin Interference Experiment Using GaAs/AlGaAs Heterostructures

We propose a spin interference (SI) experiment [1] using GaAs/AlGaAs system, where the zero-field spin-splitting ($\Delta _{0})$ is caused by the Dresselhaus term predominantly. GaAs/AlGaAs has the advantage in gating stability and long carrier mean free path relative to the other III-V materials, making it a standard semiconductor in mesoscopic physics experiment. It is shown theoretically as well as experimentally that values of $\Delta _{0}$ are generally smaller in GaAs/AlGaAs than in InGaAs/InAlAs. In the present work, however, we suggest that the gate-controllability of spins in GaAs/AlGaAs, \textit{$\beta $}$\equiv \Delta _{0}$/$k$ being the relevant parameter, should also be as good as that in InGaAs/InAlAs based on our simulations, which makes the SI experiment possible even with GaAs/AlGaAs. We fabricated a series of quantum nanowires on GaAs/AlGaAs wafers with various wire widths. We discuss their transport properties and the prospective for the future SI experiment. [1] Koga \textit{et al.}, PRB \textbf{70}, 161302(R) (2004); \textit{ibid.} \textbf{74}, 041302(R) (2006).