TY - JOUR
T1 - Induced triplet pairing in clean s -wave superconductor/ferromagnet layered structures
AU - Halterman, Klaus
AU - Valls, Oriol T.
AU - Barsic, Paul H.
PY - 2008/5/14
Y1 - 2008/5/14
N2 - We study induced triplet pairing correlations in clean ferromagnet/ superconductor/ferromagnet heterostructures. The pairing state in the superconductor is the conventional singlet s wave, and the angle α between the magnetizations of the two ferromagnetic layers is arbitrary. We use a numerical fully self-consistent solution of the microscopic equations and obtain the time-dependent triplet correlations via the Heisenberg equations of motion. We find that in addition to the usual singlet correlations, triplet correlations, which are odd in time as required by the Pauli principle, are induced in both the ferromagnets and the superconductor. These time-dependent correlations are largest at times of order of the inverse of the Debye cutoff frequency ωD, and we find that within that time scale, they are often spatially very long ranged. We discuss the behavior of the characteristic penetration lengths that describe these triplet correlations. We also find that the ferromagnets can locally magnetize the superconductor near the interface and that the local magnetization then undergoes strongly damped oscillations. The local density of states exhibits a variety of energy signatures, which we discuss, as a function of ferromagnetic strength and α.
AB - We study induced triplet pairing correlations in clean ferromagnet/ superconductor/ferromagnet heterostructures. The pairing state in the superconductor is the conventional singlet s wave, and the angle α between the magnetizations of the two ferromagnetic layers is arbitrary. We use a numerical fully self-consistent solution of the microscopic equations and obtain the time-dependent triplet correlations via the Heisenberg equations of motion. We find that in addition to the usual singlet correlations, triplet correlations, which are odd in time as required by the Pauli principle, are induced in both the ferromagnets and the superconductor. These time-dependent correlations are largest at times of order of the inverse of the Debye cutoff frequency ωD, and we find that within that time scale, they are often spatially very long ranged. We discuss the behavior of the characteristic penetration lengths that describe these triplet correlations. We also find that the ferromagnets can locally magnetize the superconductor near the interface and that the local magnetization then undergoes strongly damped oscillations. The local density of states exhibits a variety of energy signatures, which we discuss, as a function of ferromagnetic strength and α.
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U2 - 10.1103/PhysRevB.77.174511
DO - 10.1103/PhysRevB.77.174511
M3 - Article
AN - SCOPUS:43949143190
SN - 1098-0121
VL - 77
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 17
M1 - 174511
ER -