Polariton waveguides from a quantum dot chain in a nanowire photonic crystal: an architecture for quantum information science and waveguide QED

TL;DR

This paper proposes a nanowire photonic crystal waveguide with embedded quantum dots to create polariton waveguides, enabling enhanced light-matter interactions and accessible strong coupling regimes for quantum information applications.

Contribution

It introduces a novel polariton waveguide architecture based on quantum dot chains in nanowire photonic crystals, with detailed electromagnetic property calculations and potential for quantum electrodynamics experiments.

Findings

Significant increase in local optical density of states due to strong light-matter interactions.

Finite and infinite waveguide properties calculated without approximations.

Single quantum dot strong coupling regime achievable with modest dipole strengths.

Abstract

We introduce a polariton-waveguide structure, comprised of a nanowire-based photonic crystal waveguide with a quantum dot embedded in each unit cell. Using realistic designs and parameters, we derive and calculate the fundamental electromagnetic properties of these polariton waveguides, with an emphasis on the photon Green function and local optical density of states (LDOS). Both infinite and finite-size waveguides are considered, where the latter's properties are calculated using a Dyson equation approach without any approximations. We demonstrate dramatic increases, and rich fundamental control, of the LDOS due to strong light-matter interactions in each unit cell through periodic quantum dot interactions. Consequently, these structures allow the exploration of new regimes of waveguide quantum electrodynamics. As an example application, we consider the coupling of an external target quantum dot with a finite-sized polariton waveguide, and show that the single quantum dot strong coupling regime is easily accessible, even for modest dipole strengths.