# Transport and collective radiance in a basic quantum chiral optical model

## TL;DR

This paper analyzes a one-dimensional array of two-level systems with chiral coupling, revealing unidirectional excitation transport, reduced superradiance in Dicke states, and providing analytical solutions supported by numerical simulations, advancing quantum transport understanding.

## Contribution

It introduces an analytical solution for single excitation dynamics in a chiral quantum system and demonstrates the system's robustness and altered superradiance properties, supported by numerical verification.

## Key findings

- Unidirectional excitation transport is robust to emitter position fluctuations.
- Dicke states exhibit half the superradiant emission rate in unidirectional coupling.
- Analytical solutions match numerical simulations in chiral quantum systems.

## Abstract

In our work, we study the dynamics of a single excitation in an one-dimensional array of two-level systems, which are chirally coupled through a single mode waveguide. The chirality is achieved owing to a strong optical spin-locking effect, which in an ideal case gives perfect unidirectional excitation transport. We obtain a simple analytical solution for a single excitation dynamics in the Markovian limit, which directly shows the tolerance of the system with respect to the fluctuations of emitters position. We also show that the Dicke state, which is well-known to be superradiant, has twice lower emission rate in the case of unidirectional quantum interaction. Our model is supported and verified with the numerical computations of quantum emmiters coupled via surface plasmon modes in a metalic nanowire. The obtained results are based on a very general model and can be applied to any chirally coupled system, that gives a new outlook on quantum transport in chiral nanophotonics.