Emergence of 6-particle "hexciton'' states in WS${}_2$ and MoSe${}_2$ monolayers

Abstract

When doped with a high density of mobile charge carriers, monolayer transition-metal dichalcogenide (TMD) semiconductors can host new types of composite many-particle exciton states that do not exist in conventional semiconductors. Such multi-particle bound states arise when a photoexcited electron-hole pair couples to not just a single Fermi sea that is quantum-mechanically distinguishable (as for the case of conventional charged excitons or trions), but rather couples simultaneously to \textit{multiple} Fermi seas, each having distinct spin and valley quantum numbers. Composite six-particle ``hexciton'' states were recently identified in electron-doped WSe${}_2$ monolayers, but under suitable conditions they should also form in all other members of the monolayer TMD family. Here we present spectroscopic evidence demonstrating the emergence of many-body hexcitons in charge-tunable WS${}_2$ monolayers (at the A-exciton) and MoSe${}_2$ monolayers (at the B-exciton). The roles of distinguishability and carrier screening on the stability of hexcitons are discussed.

7 pages, 3 figs

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Cited by in corpus (5)

• Effects of dynamical dielectric screening on the excitonic spectrum of monolayer semiconductors
• Ten-valley excitonic complexes in charge-tunable monolayer WSe${}_2$
• Component exchange theory of trions
• Landau-level composition of bound exciton states in magnetic field
• Energy shifts and broadening of excitonic resonances in electrostatically-doped semiconductors