Dynamics of a localized spin excitation close to the spin-helix regime

Abstract

The time evolution of a local spin excitation in a (001)-confined two-dimensional electron gas subjected to Rashba and Dresselhaus spin-orbit interactions of similar strength is investigated theoretically and compared with experimental data. Specifically, the consequences of the finite spatial extension of the initial spin polarization is studied for non-balanced Rashba and Dresselhaus terms and for finite cubic Dresselhaus spin-orbit interaction. We show that the initial out-of-plane spin polarization evolves into a helical spin pattern with a wave number that gradually approaches the value $q_0$ of the persistent spin helix mode. In addition to an exponential decay of the spin polarization that is proportional to both the spin-orbit imbalance and the cubic Dresselhaus term, the finite width $w$ of the spin excitation reduces the spin polarization by a factor that approaches $\exp (-q_0^2{w}^2/2)$ at longer times.

8 pages, 7 figures

References in corpus (6)

• Electrical Detection of Spin Transport in Lateral Ferromagnet-Semiconductor Devices
• An Exact SU(2) Symmetry and Persistent Spin Helix in a Spin-Orbit Coupled System
• Emergence of the persistent spin helix in semiconductor quantum wells
• Direct mapping of the formation of a persistent spin helix: Supplementary information
• Spin dephasing and photoinduced spin diffusion in high-mobility 110-grown GaAs-AlGaAs two-dimensional electron systems
• Random walk approach to spin dynamics in a two-dimensional electron gas with spin-orbit coupling

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• Persistent Spin Helix Manipulation by Optical Doping of a CdTe Quantum Well
• Imprinting spatial helicity structure of vector vortex beam on spin texture in semiconductors
• Spin drift and diffusion in one- and two-subband helical systems
• Transition of a 2D spin mode to a helical state by lateral confinement
• Gate-Control of Anisotropic Spin Transport and Spin Helix Dynamics in a Modulation-Doped GaAs Quantum Well
• Enhanced longevity of the spin helix in low-symmetry quantum wells
• Characterization of spin-orbit fields in InGaAs quantum wells
• Spin helices in GaAs quantum wells: Interplay of electron density, spin diffusion, and spin lifetime
• Electric control of spin transport in GaAs (111) quantum wells
• Electrical control of spin relaxation anisotropy during drift transport in a two-dimensional electron gas
• Spin drift-diffusion for two-subband quantum wells
• Direct imprinting of arbitrary spin textures using programmable structured light in a semiconductor two-dimensional electron gas