Spin-polarized current oscillations in diluted magnetic semiconductor multiple quantum wells

Exciton Spin Dynamics in Semiconductor Quantum Wells

1.1 Two-Dimensional exciton fine structure The spin properties of excitons in nanostructures are determined by their fine structure. Before analysing the exciton spin dynamics, we give first a brief description of the exciton states in quantum wells. We will mainly focus in this review on GaAs or InGaAs quantum well which are model systems. For more details, the reader is referred to the review...

Spin Polarized Current Generation from Quantum Dots without Magnetic Fields

Photo-Induced Spin Dynamics in Semiconductor Quantum Wells

We experimentally investigate the dynamics of spins in GaAs quantum wells under applied electric bias by photoluminescence (PL) measurements excited with circularly polarized light. The bias-dependent circular polarization of PL (P(PL)) with and without magnetic field is studied. The P(PL) without magnetic field is found to be decayed with an enhancement of increasing the strength of the negati...

Electron-spin beat susceptibility of excitons in semiconductor quantum wells.

Recent time-resolved differential transmission and Faraday rotation measurements of long-lived electron-spin coherence in quantum wells displayed intriguing parametric dependencies. For their understanding we formulate a microscopic theory of the optical response of a gas of optically incoherent excitons whose constituent electrons retain spin coherence, under a weak magnetic field applied in t...

Adiabatic quantum pump of spin-polarized current.

We propose a mechanism by which an open quantum dot driven by two ac (radio frequency) gate voltages in the presence of a moderate in-plane magnetic field generates a spin-polarized, phase-coherent dc current. The idea combines adiabatic, nonquantized (but coherent) pumping through periodically modulated external parameters and the strong fluctuations of the electron wave function existent in c...