Singlet-triplet avoided crossings and effective $g$ factor versus spatial orientation of spin-orbit-coupled quantum dots

Abstract

We study avoided crossings opened by spin-orbit interaction in the energy spectra of one- and two-electron anisotropic quantum dots in perpendicular magnetic field. We find that for simultaneously present Rashba and Dresselhaus interactions the width of avoided crossings and the effective $g$ factor depend on the dot orientation within (001) crystal plane. The extreme values of these quantities are obtained for [110] and [1$\bar{1}$0] orientations of the dot. The width of singlet-triplet avoided crossing changes between these two orientations by as much as two orders of magnitude. The discussed modulation results from orientation-dependent strength of the Zeeman interaction which tends to polarize the spins in the direction of the external magnetic field and thus remove the spin-orbit coupling effects.

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Cited by in corpus (5)

• Electric-field dependent g-factor anisotropy in Ge-Si core-shell nanowire quantum dots
• Tuning of the spin-orbit interaction in a quantum dot by an in-plane magnetic field
• Electrical control of phonon mediated spin relaxation rate in semiconductor quantum dots: the Rashba vs the Dresselhaus spin-orbit couplings
• Spin polarization anisotropy in a narrow spin-orbit-coupled nanowire quantum dot
• Controlling the Dark Exciton Spin Eigenstates by External Magnetic Field