Intralayer charge-transfer moiré excitons in van der Waals superlattices.

Autor: Naik MH; Department of Physics, University of California at Berkeley, Berkeley, CA, USA.; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA., Regan EC; Department of Physics, University of California at Berkeley, Berkeley, CA, USA.; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.; Graduate Group in Applied Science and Technology, University of California at Berkeley, Berkeley, CA, USA., Zhang Z; Department of Physics, University of California at Berkeley, Berkeley, CA, USA., Chan YH; Department of Physics, University of California at Berkeley, Berkeley, CA, USA.; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.; Institute of Atomic and Molecular Sciences, Academia Sinica and Physics Division, National Center for Theoretical Sciences, Taipei, Taiwan., Li Z; Department of Physics, University of California at Berkeley, Berkeley, CA, USA.; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA., Wang D; Department of Physics, University of California at Berkeley, Berkeley, CA, USA.; Graduate Group in Applied Science and Technology, University of California at Berkeley, Berkeley, CA, USA., Yoon Y; Department of Physics, University of California at Berkeley, Berkeley, CA, USA.; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA., Ong CS; Department of Physics, University of California at Berkeley, Berkeley, CA, USA.; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA., Zhao W; Department of Physics, University of California at Berkeley, Berkeley, CA, USA., Zhao S; Interdisciplinary Center for Quantum Information, Zhejiang Province Key Laboratory of Quantum Technology and Device, State Key Laboratory of Silicon Materials, and Department of Physics, Zhejiang University, Hangzhou, China., Utama MIB; Department of Physics, University of California at Berkeley, Berkeley, CA, USA.; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.; Department of Materials Science and Engineering, University of California at Berkeley, Berkeley, CA, USA., Gao B; Department of Physics, University of California at Berkeley, Berkeley, CA, USA., Wei X; Department of Physics, University of California at Berkeley, Berkeley, CA, USA., Sayyad M; School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, USA., Yumigeta K; Department of Materials Science and Engineering, University of California at Berkeley, Berkeley, CA, USA., Watanabe K; Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan.; International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan., Taniguchi T; Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan.; International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan., Tongay S; School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, USA., da Jornada FH; Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA., Wang F; Department of Physics, University of California at Berkeley, Berkeley, CA, USA.; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.; Kavli Energy NanoSciences Institute at University of California Berkeley and Lawrence, Berkeley National Laboratory, Berkeley, CA, USA., Louie SG; Department of Physics, University of California at Berkeley, Berkeley, CA, USA. sglouie@berkeley.edu.; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. sglouie@berkeley.edu.
Jazyk: angličtina
Zdroj: Nature [Nature] 2022 Sep; Vol. 609 (7925), pp. 52-57. Date of Electronic Publication: 2022 Aug 31.
DOI: 10.1038/s41586-022-04991-9
Abstrakt: Moiré patterns of transition metal dichalcogenide heterobilayers have proved to be an ideal platform on which to host unusual correlated electronic phases, emerging magnetism and correlated exciton physics. Whereas the existence of new moiré excitonic states is established 1-4 through optical measurements, the microscopic nature of these states is still poorly understood, often relying on empirically fit models. Here, combining large-scale first-principles GW (where G and W denote the one-particle Green's function and the screened Coulomb interaction, respectively) plus Bethe-Salpeter calculations and micro-reflection spectroscopy, we identify the nature of the exciton resonances in WSe 2 /WS 2 moiré superlattices, discovering a rich set of moiré excitons that cannot be captured by prevailing continuum models. Our calculations show moiré excitons with distinct characters, including modulated Wannier excitons and previously unidentified intralayer charge-transfer excitons. Signatures of these distinct excitonic characters are confirmed experimentally by the unique carrier-density and magnetic-field dependences of different moiré exciton resonances. Our study highlights the highly non-trivial exciton states that can emerge in transition metal dichalcogenide moiré superlattices, and suggests new ways of tuning many-body physics in moiré systems by engineering excited-states with specific spatial characters.
(© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)
Databáze: MEDLINE
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