Phys.org June 15, 2023
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. An international team of researchers (USA – MIT, Mexico) used high pressure to tune the minibands in a rotationally aligned MoS2/WSe2 moiré heterostructure and showed that their evolution could be probed via moiré phonons. Moiré phonons manifest themselves as satellite Raman peaks. Their scattering rate was directly connected to the moiré potential strength. By comparing the experimental and calculated pressure-induced enhancement, they obtained numerical estimates for the moiré potential amplitude and its pressure dependence. According to the researchers their work establishes moiré phonons as a sensitive probe of the moiré potential as well as the electronic structures of moiré systems… read more. TECHNICAL ARTICLEÂ
… Two layers of such a material were compressed between the flat tips of two diamonds…Credit: Matheus J.S. Matos, Universidade Federal de Ouro Preto