2018/05/13 by Matteo Barbone, Alejandro R. -P. Montblanch, Dhiren M. Kara +13 · 1 citation
Physics and Astronomy · #cond-mat.mes-hall #cond-mat.mtrl-sci #quant-ph
paper · pdf · doi:10.1038/s41467-018-05632-4
arxiv created 2018/05/13 · arxiv updated 2018/10/24
Multi-exciton states such as biexcitons, albeit theoretically predicted, have remained challenging to identify in atomically thin transition metal dichalcogenides so far. Here, we use excitation-power, electric-field and magnetic-field dependence of photoluminescence to report direct experimental evidence of two biexciton complexes in monolayer tungsten diselenide: the neutral and the negatively charged biexciton. We demonstrate bias-controlled switching between these two states, we determine their internal structure and we resolve a fine-structure splitting of 2.5 meV for the neutral biexciton. Our results unveil multi-particle exciton complexes in transition metal dichalcogenides and offer direct routes to their deterministic control in many-body quantum phenomena.