Exciton dephasing in ZnSe quantum wires

Exciton dephasing in ZnSe quantum wires

Spin dephasing in quantum wires

We study high-field spin transport in a quantum wire using a semiclassical approach. Spin dephasing (or spin depolarization) in the wire is caused by D’yakonov-Perel’ relaxation associated with bulk inversion asymmetry (Dresselhaus spin-orbit coupling) and structural inversion asymmetry (Rashba spin-orbit coupling). The depolarization rate is found to depend strongly on the initial polarization...

Quasi-two-dimensional exciton in ZnSe/ZnMgSSe single quantum well

We have studied the quasi-two-dimensional exciton in ZnSe/ZnxMg12xSySe12y ~x50.85, y50.21! single quantum wells ~SQWs! by photoluminescence and photoluminescence excitation spectroscopy. Self-consistent calculations of the peak energies for a series of SQWs give the conduction band discontinuity DEc50.40DEg and the binding energy of the n51 heavy-hole exciton Eb~hh1!522.1 meV for an 8 nm well w...

Phonon-induced exciton dephasing in quantum dot molecules.

A new microscopic approach to the optical transitions in quantum dots and quantum dot molecules, which accounts for both diagonal and nondiagonal exciton-phonon interaction, is developed. The cumulant expansion of the linear polarization is generalized to a multilevel system and is applied to calculation of the full time dependence of the polarization and the absorption spectrum. In particular,...

Nonlinear optical response and exciton dephasing in quantum dots

The full time-dependent four-wave mixing polarization in quantum dots is microscopically calculated, taking into account acoustic phonon-assisted transitions between different exciton states of the dot. It is shown that quite different dephasing times of higher exciton states in pancake anisotropic InGaAs quantum dots are responsible for the experimentally observed [1] double-exponential decay ...