A microscopic approach to spin dynamics: about the meaning of spin relaxation times

Abstract

We present an approach to spin dynamics by extending the optical Bloch equations for the driven two-level system to derive microscopic expressions for the transverse and longitudinal spin relaxation times. This is done for the 6-level system of electron and hole subband states in a semiconductor or a semiconductor quantum structure to account for the degrees-of-freedom of the carrier spin and the polarization of the exciting light and includes the scattering between carriers and lattice vibrations on a microscopic level. For the subsystem of the spin-split electron subbands we treat the electron-phonon interaction in second order and derive a set of equations of motion for the 2x2 spin-density matrix which describes the electron spin dynamics and contains microscopic expressions for the longitudinal (T_1) and the transverse (T_2) spin relaxation times. Their meaning will be discussed in relation to experimental investigations of these quantities.

9 pages, 3 figures, Replacement of cond-mat/0407358 due to substantial revision

References in corpus (2)

• Spintronics: Fundamentals and applications
• High temperature spin dephasing in n-typed GaAs quantum wells

Cited by in corpus (6)

• Anisotropic spin transport in GaAs quantum wells in the presence of competing Dresselhaus and Rashba spin-orbit-coupling strengths
• Spin relaxation under identical Dresselhaus and Rashba coupling strengths in GaAs quantum wells
• Ultrafast Spin Dynamics in Optically Excited Bulk GaAs at Low Temperatures
• Electron Spin Dynamics in Impure Quantum Wells for Arbitrary Spin-Orbit Coupling
• Quasi-equilibrium optical nonlinearities in spin-polarized GaAs
• The spin-dependent semiconductor Bloch equations: a microscopic theory of Bir-Aronov-Pikus spin-relaxation