Signatures of Rashba spin-orbit interaction in the superconducting proximity effect in helical Luttinger liquids

Abstract

We consider the superconducting proximity effect in a helical Luttinger liquid at the edge of a 2D topological insulator, and derive the low-energy Hamiltonian for an edge state tunnel-coupled to a s-wave superconductor. In addition to correlations between the left and right moving modes, the coupling can induce them inside a single mode, as the spin axis of the edge modes is not necessarily constant. This can be induced controllably in HgTe/CdTe quantum wells via the Rashba spin-orbit coupling, and is a consequence of the 2D nature of the edge state wave function. The distinction of these two features in the proximity effect is also vital for the use of such helical modes in order to split Cooper-pairs. We discuss the consequent transport signatures, and point out a long-ranged feature in a dc conductance measurement that can be used to distinguish the two types of correlations present and to determine the magnitude of the Rashba interaction.

14 pages, 7 figures; Final version, numerics added

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Cited by in corpus (28)

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• Transport in two-dimensional topological materials: recent developments in experiment and theory
• Spin-helical transport in normal and superconducting topological insulators
• Helical Andreev bound states and superconducting Klein tunneling in topological insulator Josephson junctions
• Proposal for an all-electrical measurement of crossed Andreev reflection in topological insulators
• Majorana Kramers pairs in Rashba double nanowires with interactions and disorder
• Devices with electrically tunable topological insulating phases
• Backscattering in helical edge states from a magnetic impurity and Rashba disorder
• Suppression of surface p-wave superconductivity in disordered topological insulators
• Generic helical edge states due to Rashba spin-orbit coupling in a topological insulator
• Supercurrent-enabled Andreev reflection in a chiral quantum Hall edge state
• Chiral Majorana edge states in HgTe quantum wells
• Helical edge states in multiple topological mass domains
• Manipulation of Cooper pair entanglement in hybrid topological Josephson junctions
• Controllable spin entanglement production in a quantum spin Hall ring
• Levitons in helical liquids with Rashba spin-orbit coupling probed by a superconducting contact
• Fundamental limits to helical edge conductivity due to spin-phonon scattering
• Superconducting Quantum Interference in Edge State Josephson Junctions
• Crossed Andreev Re ection in Quantum Wires with Strong Spin-Orbit Interaction
• Controlling spin polarization of a quantum dot via a helical edge state
• Current correlations of Cooper-pair tunneling into a quantum Hall system
• Parity dependent Josephson current through a helical Luttinger liquid
• Reconstruction-Induced ${\phi }_0$ Josephson Effect in Quantum Spin Hall Constrictions
• Transport signatures of a quantum spin Hall - chiral topological superconductor junction
• Nonequilibrium Spectroscopy of Topological Edge Liquids
• Bulk transport through superconducting hybrid structures in HgTe quantum wells
• Spin responses of a disordered helical superconducting edge under Zeeman field