Electric-field induced spin excitations in two-dimensional spin-orbit coupled systems

Abstract

Rigorous coupled spin-charge drift-diffusion equations are derived from quantum-kinetic equations for the spin-density matrix that incorporate effects due to k-linear spin-orbit interaction, an in-plane electric field, and the elastic scattering on nonmagnetic impurities. The explicit analytical solution for the induced magnetization exhibits a pole structure, from which the dispersion relations of spin excitations are identified. Applications of the general approach refer to the excitation of long-lived field-induced spin waves by optically generated spin and charge patterns. This approach transfers methods known in the physics of space-charge waves to the treatment of spin eigenmodes. In addition, the amplification of an oscillating electric field by spin injection is demonstrated.

17 pages, 3 figures

References in corpus (14)

• An Exact SU(2) Symmetry and Persistent Spin Helix in a Spin-Orbit Coupled System
• Spin current and polarization in impure 2D electron systems with spin-orbit coupling
• On A Proper Definition of Spin Current
• Anisotropic current-induced spin accumulation in the two-dimensional electron gas with spin-orbit coupling
• Detection of large magneto-anisotropy of electron spin dephasing in a high-mobility two-dimensional electron system in a $[001]$ GaAs/AlGaAs quantum well
• Anisotropic spin transport in GaAs quantum wells in the presence of competing Dresselhaus and Rashba spin-orbit-coupling strengths
• Long-Lived Spin Coherence States
• Frequency dependence of induced spin polarization and spin current in quantum wells
• Spin diffusion/transport in $n$-type GaAs quantum wells
• Spin relaxation in $n$-type GaAs quantum wells with transient spin grating
• Spin polarization in biased Rashba-Dresselhaus two-dimensional electron systems
• Spin-Hall effect and spin-coherent excitations in a strongly confined two-dimensional hole gas
• Coupled spin-charge drift-diffusion approach for a two-dimensional electron gas with Rashba spin-orbit coupling
• Oscillation of spin polarization in a two-dimensional hole gas under a perpendicular magnetic field