Interdiffusion-controlled Kondo suppression of injection efficiency in metallic nonlocal spin valves

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Nonlocal spin valves (NLSVs) generate pure spin currents, providing unique insight into spin injection and relaxation at the nanoscale. Recently it was shown that the puzzling low temperature nonmonotonicity of the spin accumulation in all-metal NLSVs occurs due to a manifestation of the Kondo effect arising from dilute local-moment-forming impurities in the nonmagnetic material. Here it is demonstrated that precise control over interdiffusion in Fe/Cu NLSVs via thermal annealing can induce dramatic increases in this Kondo suppression of injection efficiency, observation of injector/detector separation-dependent Kondo effects in both charge and spin channels simultaneously, and, in the limit of large interdiffusion, complete breakdown of standard Valet-Fert-based models. The Kondo effect in the charge channel enables extraction of the exact interdiffusion profile, quantifying the influence of local moment density on the injection efficiency and presenting a well-posed challenge to theory.

Original languageEnglish (US)
Article number014413
JournalPhysical Review B
Volume93
Issue number1
DOIs
StatePublished - Jan 11 2016

Fingerprint

Kondo effect
retarding
injection
Metals
Annealing
Impurities
Detectors
moments
injectors
breakdown
Temperature
impurities
annealing
detectors
profiles

How much support was provided by MRSEC?

  • Partial

Reporting period for MRSEC

  • Period 2

Cite this

Interdiffusion-controlled Kondo suppression of injection efficiency in metallic nonlocal spin valves. / O'Brien, L.; Spivak, D.; Jeong, J. S.; Mkhoyan, K. A.; Crowell, P. A.; Leighton, C.

In: Physical Review B, Vol. 93, No. 1, 014413, 11.01.2016.

Research output: Contribution to journalArticle

@article{24c68536fe80489f9309df1050289403,
title = "Interdiffusion-controlled Kondo suppression of injection efficiency in metallic nonlocal spin valves",
abstract = "Nonlocal spin valves (NLSVs) generate pure spin currents, providing unique insight into spin injection and relaxation at the nanoscale. Recently it was shown that the puzzling low temperature nonmonotonicity of the spin accumulation in all-metal NLSVs occurs due to a manifestation of the Kondo effect arising from dilute local-moment-forming impurities in the nonmagnetic material. Here it is demonstrated that precise control over interdiffusion in Fe/Cu NLSVs via thermal annealing can induce dramatic increases in this Kondo suppression of injection efficiency, observation of injector/detector separation-dependent Kondo effects in both charge and spin channels simultaneously, and, in the limit of large interdiffusion, complete breakdown of standard Valet-Fert-based models. The Kondo effect in the charge channel enables extraction of the exact interdiffusion profile, quantifying the influence of local moment density on the injection efficiency and presenting a well-posed challenge to theory.",
author = "L. O'Brien and D. Spivak and Jeong, {J. S.} and Mkhoyan, {K. A.} and Crowell, {P. A.} and C. Leighton",
year = "2016",
month = "1",
day = "11",
doi = "10.1103/PhysRevB.93.014413",
language = "English (US)",
volume = "93",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "1",

}

TY - JOUR

T1 - Interdiffusion-controlled Kondo suppression of injection efficiency in metallic nonlocal spin valves

AU - O'Brien, L.

AU - Spivak, D.

AU - Jeong, J. S.

AU - Mkhoyan, K. A.

AU - Crowell, P. A.

AU - Leighton, C.

PY - 2016/1/11

Y1 - 2016/1/11

N2 - Nonlocal spin valves (NLSVs) generate pure spin currents, providing unique insight into spin injection and relaxation at the nanoscale. Recently it was shown that the puzzling low temperature nonmonotonicity of the spin accumulation in all-metal NLSVs occurs due to a manifestation of the Kondo effect arising from dilute local-moment-forming impurities in the nonmagnetic material. Here it is demonstrated that precise control over interdiffusion in Fe/Cu NLSVs via thermal annealing can induce dramatic increases in this Kondo suppression of injection efficiency, observation of injector/detector separation-dependent Kondo effects in both charge and spin channels simultaneously, and, in the limit of large interdiffusion, complete breakdown of standard Valet-Fert-based models. The Kondo effect in the charge channel enables extraction of the exact interdiffusion profile, quantifying the influence of local moment density on the injection efficiency and presenting a well-posed challenge to theory.

AB - Nonlocal spin valves (NLSVs) generate pure spin currents, providing unique insight into spin injection and relaxation at the nanoscale. Recently it was shown that the puzzling low temperature nonmonotonicity of the spin accumulation in all-metal NLSVs occurs due to a manifestation of the Kondo effect arising from dilute local-moment-forming impurities in the nonmagnetic material. Here it is demonstrated that precise control over interdiffusion in Fe/Cu NLSVs via thermal annealing can induce dramatic increases in this Kondo suppression of injection efficiency, observation of injector/detector separation-dependent Kondo effects in both charge and spin channels simultaneously, and, in the limit of large interdiffusion, complete breakdown of standard Valet-Fert-based models. The Kondo effect in the charge channel enables extraction of the exact interdiffusion profile, quantifying the influence of local moment density on the injection efficiency and presenting a well-posed challenge to theory.

UR - http://www.scopus.com/inward/record.url?scp=84955304107&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84955304107&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.93.014413

DO - 10.1103/PhysRevB.93.014413

M3 - Article

AN - SCOPUS:84955304107

VL - 93

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 1

M1 - 014413

ER -