Neutral and charged inter-valley biexcitons in monolayer MoSe2.

摘要: In atomically thin transition metal dichalcogenides (TMDs), reduced dielectric screening of the Coulomb interaction leads to strongly correlated many-body states, including excitons and trions, that dominate optical properties. Higher-order such as bound biexcitons, are possible but difficult identify unambiguously using linear spectroscopy methods. Here, we implement polarization-resolved two-dimensional coherent (2DCS) unravel complex response monolayer MoSe2 multiple higher-order states. Decisive signatures neutral charged inter-valley biexcitons appear in cross-polarized spectra distinct resonances with respective ∼20 ∼5 meV binding energies—similar recent calculations variational Monte Carlo A theoretical model considering valley-dependent selection rules reveals quantum pathways give rise these Inter-valley identified here, comprising from different valleys, offer new opportunities for developing ultrathin biexciton lasers polarization-entangled photon sources. Atomically host however although possible, experimentally. authors perform unveil signature MoSe2.