Spin injection and detection up to room temperature in Heusler alloy/ n -GaAs spin valves

T. A. Peterson; S. J. Patel; C. C. Geppert; K. D. Christie; A. Rath; D. Pennachio; M. E. Flatte; P. M. Voyles; C. J. Palmstrom; P. A. Crowell

doi:10.1103/PhysRevB.94.235309

Spin injection and detection up to room temperature in Heusler alloy/ n -GaAs spin valves

T. A. Peterson, S. J. Patel, C. C. Geppert, K. D. Christie, A. Rath, D. Pennachio, M. E. Flatte, P. M. Voyles, C. J. Palmstrom, P. A. Crowell

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49 Scopus citations

Abstract

We have measured the spin injection efficiency and spin lifetime in Co2FeSi/n-GaAs lateral nonlocal spin valves from 20 to 300 K. We observe large (∼40μV) spin valve signals at room temperature and injector currents of 103A/cm2, facilitated by fabricating spin valve separations smaller than the 1μm spin diffusion length and applying a forward bias to the detector contact. The spin transport parameters are measured by comparing the injector-detector contact separation dependence of the spin valve signal with a numerical model accounting for spin drift and diffusion. The apparent suppression of the spin injection efficiency at the lowest temperatures reflects a breakdown of the ordinary drift-diffusion model in the regime of large spin accumulation. A theoretical calculation of the D'yakonov-Perel' spin lifetime agrees well with the measured n-GaAs spin lifetime over the entire temperature range.

Original language	English (US)
Article number	235309
Journal	Physical Review B
Issue number	23
DOIs	https://doi.org/10.1103/PhysRevB.94.235309
State	Published - Dec 30 2016

Bibliographical note

Funding Information:
This work was supported by the National Science Foundation (NSF) under DMR-1104951, C-SPIN, one of the six centers of STARnet, an SRC program sponsored by MARCO and DARPA, the Materials Research Science and Engineering Centers (MRSEC) program of the NSF under DMR 08-19885 and DMR 14-20013, and the NSF NNCI program.

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© 2016 American Physical Society.

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title = "Spin injection and detection up to room temperature in Heusler alloy/ n -GaAs spin valves",

abstract = "We have measured the spin injection efficiency and spin lifetime in Co2FeSi/n-GaAs lateral nonlocal spin valves from 20 to 300 K. We observe large (∼40μV) spin valve signals at room temperature and injector currents of 103A/cm2, facilitated by fabricating spin valve separations smaller than the 1μm spin diffusion length and applying a forward bias to the detector contact. The spin transport parameters are measured by comparing the injector-detector contact separation dependence of the spin valve signal with a numerical model accounting for spin drift and diffusion. The apparent suppression of the spin injection efficiency at the lowest temperatures reflects a breakdown of the ordinary drift-diffusion model in the regime of large spin accumulation. A theoretical calculation of the D'yakonov-Perel' spin lifetime agrees well with the measured n-GaAs spin lifetime over the entire temperature range.",

author = "Peterson, {T. A.} and Patel, {S. J.} and Geppert, {C. C.} and Christie, {K. D.} and A. Rath and D. Pennachio and Flatte, {M. E.} and Voyles, {P. M.} and Palmstrom, {C. J.} and Crowell, {P. A.}",

note = "Funding Information: This work was supported by the National Science Foundation (NSF) under DMR-1104951, C-SPIN, one of the six centers of STARnet, an SRC program sponsored by MARCO and DARPA, the Materials Research Science and Engineering Centers (MRSEC) program of the NSF under DMR 08-19885 and DMR 14-20013, and the NSF NNCI program. Publisher Copyright: {\textcopyright} 2016 American Physical Society.",

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doi = "10.1103/PhysRevB.94.235309",

language = "English (US)",

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AU - Peterson, T. A.

AU - Patel, S. J.

AU - Geppert, C. C.

AU - Christie, K. D.

AU - Rath, A.

AU - Pennachio, D.

AU - Flatte, M. E.

AU - Voyles, P. M.

AU - Palmstrom, C. J.

AU - Crowell, P. A.

N1 - Funding Information: This work was supported by the National Science Foundation (NSF) under DMR-1104951, C-SPIN, one of the six centers of STARnet, an SRC program sponsored by MARCO and DARPA, the Materials Research Science and Engineering Centers (MRSEC) program of the NSF under DMR 08-19885 and DMR 14-20013, and the NSF NNCI program. Publisher Copyright: © 2016 American Physical Society.

PY - 2016/12/30

Y1 - 2016/12/30

N2 - We have measured the spin injection efficiency and spin lifetime in Co2FeSi/n-GaAs lateral nonlocal spin valves from 20 to 300 K. We observe large (∼40μV) spin valve signals at room temperature and injector currents of 103A/cm2, facilitated by fabricating spin valve separations smaller than the 1μm spin diffusion length and applying a forward bias to the detector contact. The spin transport parameters are measured by comparing the injector-detector contact separation dependence of the spin valve signal with a numerical model accounting for spin drift and diffusion. The apparent suppression of the spin injection efficiency at the lowest temperatures reflects a breakdown of the ordinary drift-diffusion model in the regime of large spin accumulation. A theoretical calculation of the D'yakonov-Perel' spin lifetime agrees well with the measured n-GaAs spin lifetime over the entire temperature range.

AB - We have measured the spin injection efficiency and spin lifetime in Co2FeSi/n-GaAs lateral nonlocal spin valves from 20 to 300 K. We observe large (∼40μV) spin valve signals at room temperature and injector currents of 103A/cm2, facilitated by fabricating spin valve separations smaller than the 1μm spin diffusion length and applying a forward bias to the detector contact. The spin transport parameters are measured by comparing the injector-detector contact separation dependence of the spin valve signal with a numerical model accounting for spin drift and diffusion. The apparent suppression of the spin injection efficiency at the lowest temperatures reflects a breakdown of the ordinary drift-diffusion model in the regime of large spin accumulation. A theoretical calculation of the D'yakonov-Perel' spin lifetime agrees well with the measured n-GaAs spin lifetime over the entire temperature range.

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Spin injection and detection up to room temperature in Heusler alloy/ n -GaAs spin valves

Abstract

Bibliographical note

How much support was provided by MRSEC?

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MRSEC IRG-1: Electrostatic Control of Materials

University of Minnesota MRSEC (DMR-1420013)

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Spin injection and detection up to room temperature in Heusler alloy/ n -GaAs spin valves

Abstract

Bibliographical note

How much support was provided by MRSEC?

Reporting period for MRSEC

Access

OpenUrl availability

Other files and links

Fingerprint

Projects

MRSEC IRG-1: Electrostatic Control of Materials

University of Minnesota MRSEC (DMR-1420013)

Cite this