Signatures of moire trions in WSe2/MoSe2 heterobilayers

Article

关键词: INTERLAYER EXCITONS;    ELECTRICAL CONTROL;    GRAPHENE;    DYNAMICS;    STATES;   

DOI  :  10.1038/s41586-021-03541-z

来源: SCIE

【 摘 要 】

Moire superlattices formed by van der Waals materials can support a wide range of electronic phases, including Mott insulators(1-4), superconductors(5-10) and generalized Wigner crystals(2). When excitons are confined by a moire superlattice, a new class of exciton emerges, which holds promise for realizing artificial excitonic crystals and quantum optical effects(11-16). When such moire excitons are coupled to charge carriers, correlated states may arise. However, no experimental evidence exists for charge-coupled moire exciton states, nor have their properties been predicted by theory. Here we report the optical signatures of trions coupled to the moire potential in tungsten diselenide/molybdenum diselenide heterobilayers. The moire trions show multiple sharp emission lines with a complex charge-density dependence, in stark contrast to the behaviour of conventional trions. We infer distinct contributions to the trion emission from radiative decay in which the remaining carrier resides in different moire minibands. Variation of the trion features is observed in different devices and sample areas, indicating high sensitivity to sample inhomogeneity and variability. The observation of these trion features motivates further theoretical and experimental studies of higher-order electron correlation effects in moire superlattices.

【 授权许可】

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