---
abstract: 'We demonstrate room temperature chiral strong coupling of valley excitons in a transition metal dichalcogenide monolayer with spin-momentum locked surface plasmons. In this regime, we measure spin-selective excitation of directional flows of polaritons. Operating under strong light-matter coupling, our platform yields robust intervalley contrasts and coherences, enabling us to generate coherent superpositions of chiral polaritons propagating in opposite directions. Our results reveal the rich and easy to implement possibilities offered by our system in the context of chiral optical networks.'
author:
- Thibault Chervy
- Stefano Azzini
- Etienne Lorchat
- Shaojun Wang
- Yuri Gorodetski
- 'James A. Hutchison'
- Stéphane Berciaud
- 'Thomas W. Ebbesen'
- Cyriaque Genet
bibliography:
- 'biblio-new-arxiv-v2.bib'
title: 'Spin-momentum locked polariton transport in the chiral strong coupling regime'
---

Optical spin-orbit (OSO) interaction couples the polarization of a light field with its propagation direction [@bliokh2015spin]. An important body of work has recently described how OSO interactions can be exploited at the level of nano-optical devices, involving dielectric [@bomzon2002space; @Kuipers2014; @Rauschenbeutel2014science; @rafayelyan2016reflective] or plasmonic architectures [@bliokhPRL2008; @gorodetski2013generating; @Capasso2013; @Zayats2013; @spektor2015; @Drezet2016], all able to confine the electromagnetic field below the optical wavelength. Optical spin-momentum locking effects have been used to spatially route the 