title: Field-induced negative differential spin lifetime in silicon.
abstract: We show that the electric-field-induced thermal asymmetry between the electron and lattice systems in pure silicon substantially impacts the identity of the dominant spin relaxation mechanism. Comparison of empirical results from long-distance spin transport devices with detailed Monte Carlo simulations confirms a strong spin depolarization beyond what is expected from the standard Elliott-Yafet theory even at low temperatures. The enhanced spin-flip mechanism is attributed to phonon emission processes during which electrons are scattered between conduction band valleys that reside on different crystal axes. This leads to anomalous behavior, where (beyond a critical field) reduction of the transit time between spin-injector and spin-detector is accompanied by a counterintuitive reduction in spin polarization and an apparent negative spin lifetime.
authors.affiliation: Department of Physics and Center for Nanophysics and Advanced Materials, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Lan
authors.initials: L
authors.lastname: Qing
authors.forename: Hanan
authors.initials: H
authors.lastname: Dery
authors.forename: Ian
authors.initials: I
authors.lastname: Appelbaum