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arXiv · 1406.7161

Transport signatures of superconducting hybrids with mixed singlet and chiral triplet states

Pablo Burset·Felix Keidel·Yukio Tanaka·Naoto Nagaosa·Björn Trauzettel
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Abstract

We propose a model for a superconductor where both spin-singlet and chiral triplet pairing amplitudes can coexist. By solving the Bogoliubov-de Gennes equations with a general pair potential that accounts for both spin states we study experimental signatures of normal metal and superconductor hybrids. The interplay between the spin-singlet and triplet correlations manifests in the appearance of two effective gaps. When the amplitude of the spin-triplet component is stronger than that of the spin-singlet, a topological phase transition into a non-trivial regime occurs. As a result, the normal metal-superconductor conductance evolves from a conventional gap profile onto an unconventional zero-bias peak. Additionally, in the topologically non-trivial phase, Andreev bound states formed at Josephson junctions present zero-energy modes; the number of those modes depends on the relative chirality of the junction. Finally, we present results for the current-phase relation and the temperature dependence of the Josephson critical current within both topological phases for several system parameters.

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Pablo Burset, Felix Keidel, Yukio Tanaka, Naoto Nagaosa, Björn Trauzettel. 2014-06-27. Transport signatures of superconducting hybrids with mixed singlet and chiral triplet states. https://doi.org/10.1103/physrevb.90.085438

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