Gate control, g factors, and spin-orbit energy of p -type GaSb nanowire quantum dot devices

Proposals for quantum information applications are frequently based on the coherent manipulation of spins confined to quantum dots. For these applications, $p$-type III-V material systems promise a reduction of the hyperfine interaction while maintaining large $g$ factors and strong spin-orbit interaction. In this Letter, we study bottom-gated device architectures to realize single and serial multiquantum dot systems in Schottky-contacted $p$-type GaSb nanowires. We find that the effect of potentials applied to gate electrodes on the nanowire is highly localized to the immediate vicinity of the gate electrode only, which prevents the formation of double quantum dots with commonly used device architectures. We further study the transport properties of a single quantum dot induced by bottom gating and find large gate-voltage dependent variations of the ${g}^{*}$ factors up to $8.1\ifmmode\pm\else\textpm\fi{}0.2$ as well as spin-orbit energies between 110 and 230 $\ensuremath{\mu}\mathrm{eV}$.