Pressure tuning of minibands in MoS 2 /WSe 2 heterostructures revealed by moiré phonons.

Autor: Pimenta Martins LG; Physics Department, Massachusetts Institute of Technology, Cambridge, MA, USA. lmartins@alum.mit.edu., Ruiz-Tijerina DA; Departamento de Física Química, Instituto de Física, Universidad Nacional Autónoma de México, Ciudad de México, Mexico., Occhialini CA; Physics Department, Massachusetts Institute of Technology, Cambridge, MA, USA., Park JH; Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA., Song Q; Physics Department, Massachusetts Institute of Technology, Cambridge, MA, USA., Lu AY; Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA., Venezuela P; Instituto de Física, Universidade Federal Fluminense, Niterói, Brazil., Cançado LG; Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil., Mazzoni MSC; Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil., Matos MJS; Departamento de Física, Universidade Federal de Ouro Preto, Ouro Preto, Brazil., Kong J; Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA. jingkong@mit.edu., Comin R; Physics Department, Massachusetts Institute of Technology, Cambridge, MA, USA. rcomin@mit.edu.
Jazyk: angličtina
Zdroj: Nature nanotechnology [Nat Nanotechnol] 2023 Oct; Vol. 18 (10), pp. 1147-1153. Date of Electronic Publication: 2023 Jun 15.
DOI: 10.1038/s41565-023-01413-3
Abstrakt: Moiré superlattices of two-dimensional heterostructures arose as a new platform to investigate emergent behaviour in quantum solids with unprecedented tunability. To glean insights into the physics of these systems, it is paramount to discover new probes of the moiré potential and moiré minibands, as well as their dependence on external tuning parameters. Hydrostatic pressure is a powerful control parameter, since it allows to continuously and reversibly enhance the moiré potential. Here we use high pressure to tune the minibands in a rotationally aligned MoS 2 /WSe 2 moiré heterostructure, and show that their evolution can be probed via moiré phonons. The latter are Raman-inactive phonons from the individual layers that are activated by the moiré potential. Moiré phonons manifest themselves as satellite Raman peaks arising exclusively from the heterostructure region, increasing in intensity and frequency under applied pressure. Further theoretical analysis reveals that their scattering rate is directly connected to the moiré potential strength. By comparing the experimental and calculated pressure-induced enhancement, we obtain numerical estimates for the moiré potential amplitude and its pressure dependence. The present work establishes moiré phonons as a sensitive probe of the moiré potential as well as the electronic structures of moiré systems.
(© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)
Databáze: MEDLINE
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