Arakawa Tomonori, Shiogai Junichi, Ciorga Mariusz, Utz Martin, Schuh Dieter, Kohda Makoto, Nitta Junsaku, Bougeard Dominique, Weiss Dieter, Ono Teruo, Kobayashi Kensuke
Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, 560-0043 Osaka, Japan.
Department of Materials Science, Tohoku University, 980-8579 Sendai, Miyagi, Japan.
Phys Rev Lett. 2015 Jan 9;114(1):016601. doi: 10.1103/PhysRevLett.114.016601. Epub 2015 Jan 7.
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.
