Role of spin-orbit coupling in the far-infrared absorption of lateral semiconductor dots

Abstract

We investigate the relevance of the spin-orbit coupling to the far-infrared absorption of two-dimensional semiconductor dots. Varying the strength of the Dresselhaus term, a mechanism feasible in experiment by changing the dot width, distinctive splittings of the Kohn peak as well as additional low energy modes are predicted in a non-interacting model. Each mode has a spatial distribution of charge, perpendicular and in-plane spin densities that correlate in a peculiar way with the frequency and polarization of the external field. We study the robustness of these features against electron-electron interactions as well as the appearance of interaction-induced additional characteristics. PACS 73.21. La,

Quantum dots based on spin properties of semiconductor heterostructures

“…To treat the interacting problem we impose no symmetry restriction in space and we solve numerically the full two-dimensional problem including the interaction within density functional theory, using a generalization of the local-spin-density approximation (LSDA) for non-collinear spin densities (see Ref. [15] for a previous application of this formalism). Within this scheme, we find that even two-electron states can be confined to the dot.…”

Kramers Degeneracy and Spin Inversion in a Lateral Quantum Dot

“…We recall that the energy scale, produced by the effective external potential V ext (r), is larger than that produced by the spin-orbit interaction (cf [35]). Therefore, it is enough to consider the expansion of the wavefunction (4) up to the first order with the respect to the strength parameter.…”

“…Plus or minus sign here are opposite to signs of u v -derivatives. In the case of the ideal spin-flip process the numerical solution of the transcendental Equation (35) for several lowest eigenvalues with quantum numbers j and n gives Rα = 1.5 . .…”

Predicted Signatures of the Intrinsic Spin Hall Effect in Closed Systems

“…Apart from these dipolar charge modes, these systems exhibit dipolar spin modes where the spin density oscillates as a dipole in a given direction. This modes are characterized by a lower energy than the dipolar charge ones [35,36].…”

“…. Therefore, manifestations of this transversal spin-dependent drift are expected also in interacting systems [36,37].…”