Spin-Orbit Interaction in Two Dimensional Systems in InAsn-Inversion Layers

Negative magnetoconductance has been observed in n -inversion layers of InAs at temperatures between 1.05 and 77 K in magnetic fields up to 1.5 T. The experimental magnetoconductance in parallel magnetic fields is well reproduced using the localization theory with the spin-orbit interaction of Maekawa and Fukuyama. The relaxalion time of inelastic scattering τ ε is 1.5×10 -12 s at 77 K, and the temperature dependence of τ ε is expressed as τ ε ∝ T -0.08 . The relaxation time of the spin-orbit interaction is 8×10 -13 s, and is independent of the temperature. However, the theory cannot reproduce the experimental magnetoconductance in a perpendicular field. This discrepancy shows that the theory should take the anisotropy of spin-orbit interaction into account.