Dissipation-driven generation of two-qubit entanglement mediated by plasmonic waveguides

TL;DR

This paper investigates how surface plasmons in metallic waveguides can be used to generate and sustain entanglement between two distant qubits, emphasizing the role of dissipation and waveguide geometry.

Contribution

It demonstrates that a V-shaped plasmonic channel outperforms a metallic cylinder for entanglement generation and analyzes the effects of dipole misalignments and external pumping.

Findings

V-shaped channels enhance entanglement efficiency

Dissipative coupling via surface plasmons is key to entanglement

External pumping can stabilize steady-state entanglement

Abstract

We study the generation of entanglement between two distant qubits mediated by the surface plasmons of a metallic waveguide. We show that a V-shaped channel milled in a flat metallic surface is much more efficient for this purpose than a metallic cylinder. The role of the misalignments of the dipole moments of the qubits, an aspect of great importance for experimental implementations, is also studied. A careful analysis of the quantum-dynamics of the system by means of a master equation shows that two-qubit entanglement generation is essentially due to the dissipative part of the effective qubit-qubit coupling provided by the surface plasmons. The influence of a coherent external pumping, needed to achieve a steady state entanglement, is discussed. Finally, we pay attention to the question of how to get information experimentally on the degree of entanglement achieved in the system.