Influence of magnetic impurities on charge transport in diffusive-normal-metal / superconductor junctions

Abstract

Charge transport in the diffusive normal metal (DN) / insulator / $s$- and -wave superconductor junctions is studied in the presence of magnetic impurities in DN in the framework of the quasiclassical Usadel equations with the generalized boundary conditions. The cases of $s$- and d-wave superconducting electrodes are considered. The junction conductance is calculated as a function of a bias voltage for various parameters of the DN metal: resistivity, Thouless energy, the magnetic impurity scattering rate and the transparency of the insulating barrier between DN and a superconductor. It is shown that the proximity effect is suppressed by magnetic impurity scattering in DN for any value of the barrier transparency. In low-transparent s-wave junctions this leads to the suppression of the normalized zero-bias conductance. In contrast to that, in high transparent junctions zero-bias conductance is enhanced by magnetic impurity scattering. The physical origin of this effect is discussed. For the d-wave junctions, the dependence on the misorientation angle $\alpha$ between the interface normal and the crystal axis of a superconductor is studied. The zero-bias conductance peak is suppressed by the magnetic impurity scattering only for low transparent junctions with $\alpha \sim 0$. In other cases the conductance of the d-wave junctions does not depend on the magnetic impurity scattering due to strong suppression of the proximity effect by the midgap Andreev resonant states.

arXiv comment11 pages, 13 figures;d-wave case added

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Cited by in corpus (13)

• Density of states and supercurrent in diffusive SNS junctions: role of nonideal interfaces and spin-flip scattering
• The role of interface transparency and spin-dependent scattering in diffusive ferromagnet/superconductor heterostructures
• Superconducting proximity effect and long-ranged triplets in dirty metallic antiferromagnets
• Signature of a crossed Andreev reflection effect (CARE) in the magnetic response of YBCO junctions with the itinerant ferromagnet SrRuO_3
• Theory of Josephson effect in chiral p-wave superconductor / diffusive normal metal / chiral p-wave superconductor junctions
• Minigap in a SN junction with paramagnetic impurities
• Theory of thermal and charge transport in diffusive normal metal / superconductor junctions
• Quantum transport in a normal metal/odd-frequency superconductor junction
• Spin-polarized proximity effect in superconducting junctions
• 0-pi transition in SFS junctions with strongly spin-dependent scattering
• Smearing origin of zero-bias conductance peak in Ag-SiO-Bi-2212 planar tunnel junctions: influence of diffusive normal metal verified with the circuit theory
• Stability of Majorana bound states in the presence of spin-flip scattering
• Meissner effect in diffusive normal metal / d-wave superconductor junctions