Crossed Andreev Re ection in Quantum Wires with Strong Spin-Orbit Interaction

TL;DR

This paper proposes a method to detect electron entanglement in quantum wires with strong spin-orbit interaction via current cross correlations, offering a spin-to-charge readout alternative to quantum spin Hall insulators.

Contribution

It introduces a theoretical framework for observing entanglement through electric current correlations in helical Luttinger liquids with tunable wire orientation.

Findings

Current correlations reflect electron entanglement.

Wire orientation controls correlation strength.

Method offers an alternative to quantum spin Hall-based detection.

Abstract

We theoretically study tunneling of Cooper pairs from an s-wave superconductor into two semiconductor quantum wires with strong spin-orbit interaction under magnetic field, which approximate helical Luttinger liquids. The entanglement of electrons within a Cooper pair can be detected by the electric current cross correlations in the wires. By controlling the relative orientation of the wires, either lithographically or mechanically, on the substrate, the current correlations can be tuned, as dictated by the initial spin entanglement. This proposal of a spin-to-charge readout of quantum correlations is alternative to a recently proposed utilization of the quantum spin Hall insulator.