g-factor anisotropy driven spin-relaxation in germanium

摘要

A unique spin depolarization mechanism, induced by the presence of g-factor anisotropy and intervalley scattering, is revealed by spin-transport measurements on long-distance germanium devices in a magnetic field longitudinal to the initial spin orientation. The confluence of electron-phonon scattering and this previously unobserved physics enables the extraction of spin lifetime solely from spin-valve measurements. We find spin lifetimes in Ge up to several hundreds of nanoseconds at low temperature, far beyond any other available experimental results. Such long spin lifetime in Ge is governed by the space inversion symmetry and time reversal symmetry of electrons near the Brillouin zone L-point.