Optically induced spin polarization of an electric current through a quantum dot

TL;DR

This paper investigates how circularly polarized light can induce spin-polarized electric currents in a quantum dot by exploiting Rabi oscillations and energy level shifts, with analysis of temperature effects.

Contribution

It introduces a method to control spin polarization in quantum dot currents using optical irradiation and Rabi oscillations, a novel approach in spintronics.

Findings

Spin-polarized currents can be selectively generated using circularly polarized light.

Energy levels in the quantum dot are shifted by the Rabi frequency, enabling control over electron spin.

Temperature influences the degree of spin polarization in the current.

Abstract

We examine electron transport through semiconductor quantum dot subject to a continuous circularly polarized optical irradiation resonant to the electron - heavy hole transition. Electrons having certain spin polarization experience Rabi oscillation and their energy levels are shifted by the Rabi frequency. Correspondingly, the equilibrium chemical potential of the leads and the lead-to-lead bias voltage can be adjusted so only electrons with spin-up polarization or only electrons with spin-down polarization contribute to the current. The temperature dependence of the spin polarization of the current is also discussed.