title: Shot noise induced by nonequilibrium spin accumulation.
abstract: When an electric current passes across a potential barrier, the partition process of electrons at the barrier gives rise to the shot noise, reflecting the discrete nature of the electric charge. Here we report the observation of excess shot noise connected with a spin current which is induced by a nonequilibrium spin accumulation in an all-semiconductor lateral spin-valve device. We find that this excess shot noise is proportional to the spin current. Additionally, we determine quantitatively the spin-injection-induced electron temperature by measuring the current noise. Our experiments show that spin accumulation driven shot noise provides a novel means of investigating nonequilibrium spin transport.
authors.affiliation: Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, 560-0043 Osaka, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Arakawa
authors.affiliation: Department of Materials Science, Tohoku University, 980-8579 Sendai, Miyagi, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Shiogai
authors.affiliation: Institute of Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Ciorga
authors.affiliation: Institute of Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Utz
authors.affiliation: Institute of Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Schuh
authors.affiliation: Department of Materials Science, Tohoku University, 980-8579 Sendai, Miyagi, Japan and PRESTO, Japan Science and Technology Agency, 332-0012 Kawaguchi, Saitama, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kohda
authors.affiliation: Department of Materials Science, Tohoku University, 980-8579 Sendai, Miyagi, Japan.
authors.forename: Junsaku
authors.initials: J
authors.lastname: Nitta
authors.affiliation: Institute of Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany.
authors.forename: Dominique
authors.initials: D
authors.lastname: Bougeard
authors.affiliation: Institute of Experimental and Applied Physics, University of Regensburg, D-93040 Regensburg, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Weiss
authors.affiliation: Institute for Chemical Research, Kyoto University, 611-0011 Uji, Kyoto, Japan.
authors.forename: Teruo
authors.initials: T
authors.lastname: Ono
authors.affiliation: Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, 560-0043 Osaka, Japan.
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kobayashi