Coherent spin dynamics in quantum wells in quantizing magnetic field

TL;DR

This paper theoretically studies the coherent spin relaxation of photoexcited electrons in quantum wells under magnetic fields, revealing how relaxation times and spin polarization oscillations depend on electron energy, g-factor, and disorder, aiding in material characterization.

Contribution

It provides a theoretical analysis of spin relaxation times and polarization oscillations in quantum wells, linking these to magnetic field and disorder characteristics, which was not previously detailed.

Findings

Relaxation times range from 100 to 1000 ps.

Spin polarization exhibits oscillations during relaxation.

Spin relaxation depends on magnetic field and disorder scale.

Abstract

We investigate theoretically the coherent longitudinal and transversal spin relaxation of photoexcited electrons in quantum wells in quantized magnetic fields. We find the relaxation time for typical quantum well parameters between 100 and 1000 ps. For a realistic random potential the relaxation process depends on the electron energy and g-factor, demonstrating oscillations in the spin polarization accompanying the spin relaxation. The dependence of spin relaxation on applied field, and thus on the corresponding "magnetic" length, can be used to characterize the spatial scale of disorder in quantum wells.