Majorana Entanglement Bridge

TL;DR

This paper investigates how Majorana bound states can facilitate long-range entanglement between quantum dots, providing analytical insights into the dynamics and parameters influencing entanglement generation in Majorana-based systems.

Contribution

It introduces the concept of a 'Majorana entanglement bridge' and derives analytical expressions for static and dynamic concurrence in interacting Majorana devices.

Findings

Long-range entanglement with distance-independent concurrence is achievable.

The entanglement dynamics depend on parameters like island charge and charging energy.

Elastic cotunneling and crossed Andreev reflection govern entanglement formation.

Abstract

We study the concurrence of entanglement between two quantum dots in contact to Majorana bound states on a floating superconducting island. The distance between the Majorana states, the charging energy of the island, and the average island charge are shown to be decisive parameters for the efficiency of entanglement generation. We find that long-range entanglement with basically distance-independent concurrence is possible over wide parameter regions, where the proposed setup realizes a "Majorana entanglement bridge". We also study the time-dependent concurrence obtained after one of the tunnel couplings is suddenly switched on, which reveals the timescales for generating entanglement. Accurate analytical expressions for the concurrence are derived both for the static and the time-dependent case. Our results indicate that entanglement formation in interacting Majorana devices can be fully understood in terms of an interplay of elastic cotunneling (also referred to as "teleportation") and crossed Andreev reflection processes.