Valley-selective optical Stark effect of exciton-polaritons in a monolayer semiconductor
Abstract
Selective breaking of degenerate energy levels is a well-known tool for coherent manipulation of spin states. Though most simply achieved with magnetic fields, polarization-sensitive optical methods provide high-speed alternatives. Exploiting the optical selection rules of transition metal dichalcogenide monolayers, the optical Stark effect allows for ultrafast manipulation of valley-coherent excitons. Compared to excitons in these materials, microcavity exciton-polaritons offer a promising alternative for valley manipulation, with longer lifetimes, enhanced valley coherence, and operation across wider temperature ranges. Here, we show valley-selective control of polariton energies in WS2 using the optical Stark effect, extending coherent valley manipulation to the hybrid light-matter regime. Ultrafast pump-probe measurements reveal polariton spectra with strong polarization contrast originating from valley-selective energy shifts. This demonstration of valley degeneracy breaking at picosecond timescales establishes a method for coherent control of valley phenomena in exciton-polaritons.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 26, 2021
- Source ID
- 10.1038/s41467-021-24764-8
Entities
People
- Akshay A Murthy
- Erik J. Lenferink
- Hongfei Zeng
- Jovan Nelson
- Mark Hersam
- Nathaniel Stern
- Samuel H. Amsterdam
- Tobin J. Marks
- Trevor Lamountain
- Vinayak P. Dravid
Organizations
- National Science Foundation
- Office of Naval Research