Reconsideration of the spin–orbit interaction for an electron confined in a quasi-two-dimensional quantum dot: II. Bulkiness and in-plane spin–orbit coupling

Abstract

We solve the Pauli equation for the quasi-two-dimensional (2D) quantum dot (QD) system numerically by employing the finite difference technique, and reconsider how bulkiness changes the electronic structure through the spin–orbit (SO) interaction. By decomposing the internal SO coupling induced by the confinement potential into the out-of-plane and in-plane components, we demonstrate that the in-plane SO coupling produces the characteristic electronic structure having the opposite spin hybridization. The second-order perturbation approach reveals that this in-plane SO coupling has a function similar to that of Rashba SO coupling and produces the symmetry-broken spin distribution via the interstate interference. We further determine the spin precession by the internal SO coupling and investigate the optimal spin polarization to reduce the spin “fluctuation” effectively.