The optical properties of monolayer transition metal dichalcogenides are dominated by tightly-bound excitons. They form at distinct valleys in reciprocal space, and can interact via the valley-exchange coupling, modifying their dispersion considerably. Here, we predict that angle-resolved photoluminescence can be used to probe the changes of the excitonic dispersion. The exchange-coupling leads to a unique angle dependence of the emission intensity for both circularly and linearly-polarised light. We show that these emission characteristics can be strongly tuned by an external magnetic field due to the valley-specific Zeeman-shift. We propose that angle-dependent photoluminescence measurements involving both circular and linear optical polarisation as well as magnetic fields should act as strong verification of the role of valley-exchange coupling on excitonic dispersionand its signatures in optical spectra
@article{arxiv.2111.10237,
title = {Valley-exchange coupling probed by angle-resolved photoluminescence},
author = {Joshua J. P Thompson and Samuel Brem and Hanlin Fang and Carlos Antón-Solanas and Bo Han and Hangyong Shan and Saroj P. Dash and Witlef Wieczorek and Christian Schneider and Ermin Malic},
journal= {arXiv preprint arXiv:2111.10237},
year = {2021}
}