title: Thermal spin injection and accumulation in CoFe/MgO/n-type Ge contacts.
abstract: Understanding the interplay between spin and heat is a fundamental and intriguing subject. Here we report thermal spin injection and accumulation in CoFe/MgO/n-type Ge contacts with an asymmetry of tunnel spin polarization. Using local heating of electrodes by laser beam or electrical current, the thermally-induced spin accumulation is observed for both polarities of the temperature gradient across the tunnel contact. We observe that the magnitude of thermally injected spin signal scales linearly with the power of local heating of electrodes, and its sign is reversed as we invert the temperature gradient. A large Hanle magnetothermopower (HMTP) of about 7.0% and the Seebeck spin tunneling coefficient of larger than 0.74 meV K(-1) are obtained at room temperature.
authors.affiliation: Department of Physics and Center for Nanospinics of Spintronic Materials, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea.
authors.forename: Kun-Rok
authors.initials: KR
authors.lastname: Jeon
authors.forename: Byoung-Chul
authors.initials: BC
authors.lastname: Min
authors.forename: Seung-Young
authors.initials: SY
authors.lastname: Park
authors.forename: Kyeong-Dong
authors.initials: KD
authors.lastname: Lee
authors.forename: Hyon-Seok
authors.initials: HS
authors.lastname: Song
authors.forename: Youn-Ho
authors.initials: YH
authors.lastname: Park
authors.forename: Young-Hun
authors.initials: YH
authors.lastname: Jo
authors.forename: Sung-Chul
authors.initials: SC
authors.lastname: Shin