Critical Current Suppression in a Superconductor by Injection of Spin-Polarized Carriers from a Ferromagnet

Vas'ko, V. A.; Larkin, V. A.; Kraus, Patrick; Nikolaev, K. R.; Grupp, D. E.; Nordman, C.; Goldman, A. M.

doi:10.1103/physrevlett.78.1134

Cited by 271 publications

(132 citation statements)

References 16 publications

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“…LCMO is a relatively bad metal and many collision events will result in electrons being scattered into the YBCO. These electrons will be highly spin polarized and are expected to cause T c depression by pair breaking as previously discussed by other authors [40][41][42] if the YBCO thickness is smaller than the spin diffusion length, l S . An estimate of l S in YBCO can be obtained using the relation l S = ͑l 0 v F S ͒ 0.5 , 41 where S is the spin-polarized quasiparticle diffusion time, v F is the Fermi velocity, and l 0 is the electron mean free path.…”

Section: Resultsmentioning

confidence: 80%

Spin diffusion versus proximity effect at ferromagnet/superconductorLa0.7Ca0.3MnO3∕YBa2Cu3O
Peña
¹
,
Visani
²
,
García‐Barriocanal
³

et al. 2006
Phys. Rev. B
54
1
25
1
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We report on the interplay between magnetism and superconductivity in La 0.7 Ca 0.3 MnO 3 /YBa 2 Cu 3 O 7 structures. We have grown heterostructures ͑bilayers and trilayers͒ with a constant thickness of the ferromagnetic layer of 40 unit cells ͑15 nm͒ and changing the thickness of the superconductor between 1 ͑1.2 nm͒ and 40 unit cells ͑48 nm͒. The critical temperature of the bilayers decreases when the thickness of the superconductor is reduced below 10 unit cells, thus providing an estimate of the length scale of superconductivity suppression by spin-polarized quasiparticles in YBa 2 Cu 3 O 7−␦ ͑YBCO͒ of 10 nm, much larger than the coherence length. For thickness of the YBCO layer smaller than 4 unit cells; a second mechanism of superconductivity depression comes into play, probably related to the ferromagnetic/superconducting proximity effect. The relative importance in depressing the critical temperature of intrinsic mechanisms ͑quasiparticle diffusion and proximity effect͒ and extrinsic ones ͑intralayer disorder, interface roughness, or reduced dimensionality of ultrathin layers͒ is discussed.

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Section: Resultsmentioning

confidence: 80%

Spin diffusion versus proximity effect at ferromagnet/superconductorLa0.7Ca0.3MnO3∕YBa2Cu3O
Peña
¹
,
Visani
²
,
García‐Barriocanal
³

et al. 2006
Phys. Rev. B
54
1
25
1
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“…(14). In the parallel magnetization alignment, there is no spin accumulation and the current I 0 is given by the familiar result for N-S-N systems with the total N-S junction conductance g ↑ + g ↓ :…”

Section: Theoretical Resultsmentioning

confidence: 99%

Current and spin torque in double tunnel barrier ferromagnet-superconductor- ferromagnet systems

Tserkovnyak

Brataas

2002

Phys. Rev. B

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We calculate the current and the spin torque in small symmetric double tunnel barrier ferromagnet-superconductor-ferromagnet (F-S-F ) systems. Spin accumulation on the superconductor governs the transport properties when the spin-flip relaxation time is longer than the transport dwell time. In the elastic transport regime, it is demonstrated that the relative change in the current (spin torque) for F-S-F systems equals the relative change in the current (spin torque) for ferromagnet-normal metal-ferromagnet (F-N-F ) systems upon changing the relative magnetization direction of the two ferromagnets. This differs from the results in the inelastic transport regime where spin accumulation suppresses the superconducting gap and dramatically changes the magnetoresistance [S. Takahashi, H. Imamura, and S. Maekawa, Phys. Rev. Lett. 82, 3911 (1999)]. The experimental relevance of the elastic and inelastic transport regimes, respectively, as well as the reasons for the change in the transport properties are discussed.

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“…In an earlier theoretical work, 5 this effect was studied in the zero-bias limit. Several recent spin injection experiments [6][7][8][9] have been done with high-T c superconductors. Common to both ferromagnetconventional and high-T c superconductor junctions, the subgap conductance at a given bias is suppressed due to the suppression of AR by the spin splitting of energy band in the ferromagnet.…”

Section: Introductionmentioning

confidence: 99%

Proximity effect, quasiparticle transport, and local magnetic moment in ferromagnet–d-wave-superconductor junctions

Zhu

Ting

2000

Phys. Rev. B

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The proximity effect, quasiparticle transport, and local magnetic moment in ferromagnet-d-wave superconductor junctions with {110}-oriented interface are studied by solving self-consistently the Bogoliubov-de Gennes equations within an extended Hubbard model. It is found that the proximity induced order parameter oscillates in the ferromagnetic region. The modulation period is shortened with the increased exchange field while the oscillation amplitude is depressed by the interfacial scattering. With the determined superconducting energy gap, a transfer matrix method is proposed to compute the subgap conductance within a scattering approach. Many novel features including the zero-bias conductance dip and splitting are exhibited with appropriate values of the exchange field and interfacial scattering strength. The conductance spectrum can be influenced seriously by the spin-flip interfacial scattering. In addition, a sizable local magnetic moment near the {110}-oriented surface of the d-wave superconductor is discussed.

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Critical Current Suppression in a Superconductor by Injection of Spin-Polarized Carriers from a Ferromagnet

Cited by 271 publications

References 16 publications

Spin diffusion versus proximity effect at ferromagnet/superconductorLa0.7Ca0.3MnO3∕YBa2Cu3O
Peña
¹
,
Visani
²
,
García‐Barriocanal
³

et al. 2006
Phys. Rev. B
54
1
25
1
View full text Add to dashboard Cite

Spin diffusion versus proximity effect at ferromagnet/superconductorLa0.7Ca0.3MnO3∕YBa2Cu3O
Peña
¹
,
Visani
²
,
García‐Barriocanal
³

et al. 2006
Phys. Rev. B
54
1
25
1
View full text Add to dashboard Cite

Current and spin torque in double tunnel barrier ferromagnet-superconductor- ferromagnet systems

Proximity effect, quasiparticle transport, and local magnetic moment in ferromagnet–d-wave-superconductor junctions

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Critical Current Suppression in a Superconductor by Injection of Spin-Polarized Carriers from a Ferromagnet

Cited by 271 publications

References 16 publications

Spin diffusion versus proximity effect at ferromagnet/superconductorLa0.7Ca0.3MnO3∕YBa2Cu3OPeña1, Visani2, García‐Barriocanal3 et al. 2006Phys. Rev. B541251View full textAdd to dashboardCite

Spin diffusion versus proximity effect at ferromagnet/superconductorLa0.7Ca0.3MnO3∕YBa2Cu3OPeña1, Visani2, García‐Barriocanal3 et al. 2006Phys. Rev. B541251View full textAdd to dashboardCite

Current and spin torque in double tunnel barrier ferromagnet-superconductor- ferromagnet systems

Proximity effect, quasiparticle transport, and local magnetic moment in ferromagnet–d-wave-superconductor junctions

Contact Info

Product

Resources

About

Spin diffusion versus proximity effect at ferromagnet/superconductorLa0.7Ca0.3MnO3∕YBa2Cu3O
Peña
¹
,
Visani
²
,
García‐Barriocanal
³

et al. 2006
Phys. Rev. B
54
1
25
1
View full text Add to dashboard Cite

Spin diffusion versus proximity effect at ferromagnet/superconductorLa0.7Ca0.3MnO3∕YBa2Cu3O
Peña
¹
,
Visani
²
,
García‐Barriocanal
³

et al. 2006
Phys. Rev. B
54
1
25
1
View full text Add to dashboard Cite