Phase-tunable electron transport assisted by odd-frequency Cooper pairs in topological Josephson junctions

Abstract

We consider a finite-size topological Josephson junction formed at the edge of a two-dimensional topological insulator in proximity to conventional superconductors and study the impact of Cooper pair symmetries on the electron transport. We find that, due to the finite junction size, electron transport is highly tunable by the superconducting phase difference $\varphi$ across the junction. At zero frequency and $\varphi =\pi$, the setup exhibits vanishing local Andreev reflection and perfect normal transmission due to the interplay of finite junction size and formation of topological Andreev bound states in the middle of the junction. We reveal that this striking behavior enables odd-frequency Cooper pairs to become the only type of pairing inside the topological junction that contribute to transport. Our paper thus offers a highly tunable detection scheme for odd-frequency Cooper pairs.

7 pages, 3 figures + 9 pages supplemental material, 2 figures

References in corpus (11)

• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Edge-mode Superconductivity in a Two Dimensional Topological Insulator
• Symmetries of Pairing Correlations in Superconductor-Ferromagnet Nanostructures
• Odd-frequency pairing in normal metal/superconductor junctions
• Fermion-parity anomaly of the critical supercurrent in the quantum spin-Hall effect
• Signature of magnetic-dependent gapless odd frequency states at superconductor/ferromagnet interfaces
• Spin-helical transport in normal and superconducting topological insulators
• Odd-frequency superconducting pairing and subgap density of states at the edge of a two-dimensional topological insulator without magnetism
• Dirac Green's function approach to graphene-superconductor junctions with well defined edges
• Odd-frequency superconductivity in dilute magnetic superconductors
• Spin injection and spin relaxation in odd-frequency superconductors

Cited by in corpus (4)

• Zero-frequency supercurrent susceptibility signatures of trivial and topological zero-energy states in nanowire junctions
• Odd-frequency pairs and anomalous proximity effect in nematic and chiral states of superconducting topological insulators
• Phase-tunable multiple Andreev reflections in a quantum spin Hall strip
• Phase-dependent charge and heat current in thermally biased short Josephson junctions formed at helical edge states