Intervalley scattering and weak localization in Si-based two-dimensional structures

摘要: We have measured the weak localization magnetoresistance in (001)-oriented Si metal-oxide-semiconductor structures with a wide range of mobilities. For quantitative analysis data, we extended theory weak-localization corrections ballistic regime to system two equivalent valleys electron spectrum. This describes observed and allows extraction phase breaking time, ${\ensuremath{\tau}}_{\ensuremath{\varphi}}$, intervalley scattering ${\ensuremath{\tau}}_{v}$. The temperature dependences, ${\ensuremath{\tau}}_{\ensuremath{\varphi}}(T)$, for all studied are good agreement electron-electron interaction effects two-dimensional systems. is elastic rather strong: ${\ensuremath{\tau}}_{v}$ typically only an order magnitude greater than transport $\ensuremath{\tau}$. It found that rate temperature-independent ratio ${\ensuremath{\tau}}_{v}∕\ensuremath{\tau}$ decreases increasing density. These observations suggest roughness $\mathrm{Si}\text{\ensuremath{-}}\mathrm{Si}{\mathrm{O}}_{2}$ interface plays major role scattering.