Cooper-Pair Injection into Quantum Spin Hall Insulators

Abstract

We theoretically study tunneling of Cooper pairs from a superconductor spanning a two-dimensional topological insulator strip into its helical edge states. The coherent low-energy electron-pair tunneling sets off positive current cross correlations along the edges, which reflect an interplay of two quantumentanglement processes. Most importantly, superconducting spin pairing dictates a Cooper pair partitioning into the helical edge liquids, which transport electrons in opposite directions for opposite spin orientations. At the same time, Luttinger-liquid correlations fractionalize electrons injected at a given edge into counterpropagating charge pulses carrying definite fractions of the elementary electron charge.

5 pages and 1 figure

References in corpus (5)

• Non-Abelian Anyons and Topological Quantum Computation
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• The Helical Liquid and the Edge of Quantum Spin Hall Systems
• Edge Dynamics in a Quantum Spin Hall State: Effects from Rashba Spin-Orbit Interaction
• Tunneling between edge states in a quantum spin Hall system

Cited by in corpus (6)

• Kramers Pairs of Majorana Fermions and Parafermions in Fractional Topological Insulators
• Signatures of nonlocal Cooper-pair transport and of a singlet-triplet transition in the critical current of a double-quantum-dot Josephson junction
• Controllable spin entanglement production in a quantum spin Hall ring
• Detection of spin entanglement via spin-charge separation in crossed Tomonaga-Luttinger liquids
• Magnetic-field switchable metal-insulator transitions in a quasi-helical conductor
• Nonlocal Andreev reflection, fractional charge and current-phase relation in topological bilayer exciton condensate junctions