Spin-orbit excitations of quantum wells

TL;DR

This paper investigates how spin-orbit coupling influences the photoabsorption properties of quantum wells, revealing that spin-orbit interaction induces non-zero excitation strength and energy, with Coulomb interactions having minimal impact.

Contribution

It introduces a sum-rules approach incorporating Rashba spin-orbit coupling and derives simple expressions for excitation strength and energy, including the effects of electron-electron correlations.

Findings

Spin-orbit coupling induces non-zero excitation strength in quantum wells.

Derived simple expressions for excitation properties up to second order in Rashba parameter.

Electron-electron interactions cause only small deviations from independent particle predictions.

Abstract

Confinement asymmetry effects on the photoabsorption of a quantum well are discussed by means of a sum-rules approach using a Hamiltonian including a Rashba spin-orbt coupling. We show that while the strength of the excitation is zero when the spin-orbit coupling is neglected, the inclusion of the spin-orbit interaction gives rise to a non zero strength and mean excitation energy in the far-infrared region. A simple expression for these quantities up to the second order in the Rashba parameter was derived. The effect of two-body Coulomb interaction is then studied by means of a Quantum Monte Carlo calculation, showing that electron-electron correlations induce only a small deviation from the independent particle model result.