Spin dynamics in high-mobility two-dimensional electron systems

Abstract

Understanding the spin dynamics in semiconductor heterostructures is highly important for future semiconductor spintronic devices. In high-mobility two-dimensional electron systems (2DES), the spin lifetime strongly depends on the initial degree of spin polarization due to the electron-electron interaction. The Hartree-Fock (HF) term of the Coulomb interaction acts like an effective out-of-plane magnetic field and thus reduces the spin-flip rate. By time-resolved Faraday rotation (TRFR) techniques, we demonstrate that the spin lifetime is increased by an order of magnitude as the initial spin polarization degree is raised from the low-polarization limit to several percent. We perform control experiments to decouple the excitation density in the sample from the spin polarization degree and investigate the interplay of the internal HF field and an external perpendicular magnetic field. The lifetime of spins oriented in the plane of a [001]-grown 2DES is strongly anisotropic if the Rashba and Dresselhaus spin-orbit fields are of the same order of magnitude. This anisotropy, which stems from the interference of the Rashba and the Dresselhaus spin-orbit fields, is highly density-dependent: as the electron density is increased, the kubic Dresselhaus term becomes dominant and reduces the anisotropy.

13 pages, 6 figures

References in corpus (8)

• High temperature spin dephasing in n-typed GaAs quantum wells
• Effect of initial spin polarization on spin dephasing and electron g factor in a high-mobility two-dimensional electron system
• Hot-electron effect in spin dephasing in $n$-type GaAs quantum wells
• Spin relaxation in $n$-type GaAs quantum wells from a full microscopic approach
• Kinetic theory of spin transport in n-typed semiconductor quantum wells
• Detection of large magneto-anisotropy of electron spin dephasing in a high-mobility two-dimensional electron system in a $[001]$ GaAs/AlGaAs quantum well
• Multi-subband effect in spin dephasing in semiconductor quantum wells
• Drift and Diffusion of Spins Generated by the Spin Hall Effect

Cited by in corpus (2)

• Electron spin relaxation in bulk III-V semiconductors from a fully microscopic kinetic spin Bloch equation approach
• Electron spin relaxation in paramagnetic Ga(Mn)As quantum wells