title: Experimental Demonstration of Room-Temperature Spin Transport in n-Type Germanium Epilayers.
abstract: We report an experimental demonstration of room-temperature spin transport in n-type Ge epilayers grown on a Si(001) substrate. By utilizing spin pumping under ferromagnetic resonance, which inherently endows a spin battery function for semiconductors connected with a ferromagnet, a pure spin current is generated in the n-Ge at room temperature. The pure spin current is detected by using the inverse spin-Hall effect of either a Pt or Pd electrode on n-Ge. From a theoretical model that includes a geometrical contribution, the spin diffusion length in n-Ge at room temperature is estimated to be 660 nm. Moreover, the spin relaxation time decreases with increasing temperature, in agreement with a recently proposed theory of donor-driven spin relaxation in multivalley semiconductors.
authors.affiliation: Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Dushenko
authors.affiliation: Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Koike
authors.affiliation: Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan.|Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ando
authors.affiliation: Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Shinjo
authors.affiliation: Department of Physics, The University of Warwick, Coventry CV47AL, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Myronov
authors.affiliation: Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan.|Department of Electronic Science and Engineering, Kyoto University, Kyoto 615-8510, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Shiraishi