Spin noise spectroscopy in GaAs (110) quantum wells: Access to intrinsic spin lifetimes and equilibrium electron dynamics

TL;DR

This paper demonstrates spin noise spectroscopy in GaAs (110) quantum wells, revealing intrinsic electron spin lifetimes and equilibrium electron dynamics without disturbing the system, providing new insights into low-dimensional semiconductor spin behavior.

Contribution

First application of spin noise spectroscopy in semiconductor quantum wells, enabling access to intrinsic spin relaxation times and equilibrium electron dynamics.

Findings

Measured intrinsic low-temperature electron spin relaxation times.

Observed anisotropic spin relaxation in GaAs (110) quantum wells.

Studied electron dynamics at equilibrium through spatially resolved spin noise.

Abstract

In this letter, the first spin noise spectroscopy measurements in semiconductor systems of reduced effective dimensionality are reported. The non-demolition measurement technique gives access to the otherwise concealed intrinsic, low temperature electron spin relaxation time of n-doped GaAs (110) quantum wells and to the corresponding low temperature anisotropic spin relaxation. The Brownian motion of the electrons within the spin noise probe laser spot becomes manifest in a modification of the spin noise line width. Thereby, the spatially resolved observation of the stochastic spin polarization uniquely allows to study electron dynamics at equilibrium conditions with a vanishing total momentum of the electron system.