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

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.

12 pages, 6 figures

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Cited by in corpus (11)

• Odd-frequency superconducting pairing and subgap density of states at the edge of a two-dimensional topological insulator without magnetism
• Creation of spin-triplet Cooper pairs in the absence of magnetic ordering
• Transport spectroscopy of induced superconductivity in the three-dimensional topological insulator HgTe
• Theory of proximity effect in $s+p$-wave superconductor junctions
• Conduction spectroscopy of a proximity induced superconducting topological insulator
• Signature of Anomalous Andreev bound states in magnetic Josephson junction of noncentrosymmetric superconductor on a topological insulator
• Proximity effect of time-reversal symmetry broken non-centrosymmetric superconductors
• Probing the topological character of superconductors via non-local Hanbury-Brown and Twiss correlations
• Spin conductance in SNN junctions with non-centrosymmetric superconductors
• Probing the dichotomy between Yu-Shiba-Rusinov and Majorana bound states via conductance, quantum noise and ${\Delta }_T$ noise
• Effects due to unconventional pairing in transport through a normal metalsuperconductor-normal metal hybrid junction