Doping Dependence of Spin Dynamics of Drifting Electrons in GaAs Bulks

作者：Spezia S^*; Adorno D Persano; Pizzolato N; Spagnolo B

来源：Acta Physica Polonica, A, 2011, 119(2): 250-252.

We study the effect of the impurity density on lifetimes and relaxation lengths of electron spins in the presence of a static electric field in an n-type GaAs bulk. The transport of electrons and the spin dynamics are simulated by using a semiclassical Monte Carlo approach, which takes into account the intravalley scattering mechanisms of warm electrons in the semiconductor material. Spin relaxation is considered through the D'yakonov-Perel mechanism, which is the dominant mechanism in III-V semiconductors. The evolution of spin polarization is analyzed by computing lifetimes and depolarization lengths as a function of the doping density in the range 10(13) divided by 5 x 10(16) cm(-3), for different values of the amplitude of the static electric field (0.1 divided by 1.0 kV/cm). We find an increase of the electron spin lifetime as a function of the doping density, more evident for lattice temperatures lower than 150 K. Moreover, at very low intensities of the driving field, the spin depolarization length shows a nonmonotonic behaviour with the density. At the room temperature, spin lifetimes and depolarization lengths are nearly independent on the doping density. The underlying physics is analyzed.

• 出版日期2011-2