Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Andreev reflection and subgap transport due to electron-magnon interactions in ferromagnet-superconductor junctions.
AU - Tkachov, G.
AU - McCann, E.
AU - Falko, Vladimir
PY - 2003/11/10
Y1 - 2003/11/10
N2 - We show that electron-magnon interactions at a ferromagnetic metal-superconductor interface lead to a new process of magnon-assisted Andreev reflection, which consists of the simultaneous injection of a Cooper pair from the superconductor and the emission of a magnon inside the ferromagnet. At low temperature this process represents an additional channel for subgap transport across an FS interface, which lifts restrictions on the current I resulting from the necessity to match spin-polarised current in the ferromagnet with spin-less current in the superconductor. We calculate I using the tunnelling Hamiltonian method and the nonequilibrium (Keldysh) Green functions technique. It is shown that the inelastic magnon-assisted Andreev process would manifest itself as a nonlinear addition to the I(V) characteristics which is asymmetric with respect to the sign of the bias voltage and is related to the local density of states of magnons at the interface.
AB - We show that electron-magnon interactions at a ferromagnetic metal-superconductor interface lead to a new process of magnon-assisted Andreev reflection, which consists of the simultaneous injection of a Cooper pair from the superconductor and the emission of a magnon inside the ferromagnet. At low temperature this process represents an additional channel for subgap transport across an FS interface, which lifts restrictions on the current I resulting from the necessity to match spin-polarised current in the ferromagnet with spin-less current in the superconductor. We calculate I using the tunnelling Hamiltonian method and the nonequilibrium (Keldysh) Green functions technique. It is shown that the inelastic magnon-assisted Andreev process would manifest itself as a nonlinear addition to the I(V) characteristics which is asymmetric with respect to the sign of the bias voltage and is related to the local density of states of magnons at the interface.
U2 - 10.1142/S0217979203020120
DO - 10.1142/S0217979203020120
M3 - Journal article
VL - 17
SP - 5001
EP - 5005
JO - International Journal of Modern Physics B
JF - International Journal of Modern Physics B
SN - 0217-9792
IS - 28
ER -