Collective Charge Excitations between Moiré Minibands in Twisted WSe_{2} Bilayers Probed with Resonant Inelastic Light Scattering

• Published in: Physical review letters Vol. 133; no. 4; p. 046902
• Main Authors: Saigal, Nihit, Klebl, Lennart, Lambers, Hendrik, Bahmanyar, Sina, Antić, Veljko, Kennes, Dante M, Wehling, Tim O, Wurstbauer, Ursula
• Format: Journal Article
• Language: English
• Published: United States 26-07-2024
• ISSN: 1079-7114; 1079-7114
• DOI: 10.1103/PhysRevLett.133.046902

We establish low-temperature resonant inelastic light scattering (RILS) spectroscopy as a tool to probe the formation of a series of moiré bands in twisted WSe_{2} bilayers by accessing collective inter-moiré-band excitations (IMBEs). We observe resonances in RILS spectra at energies in agreement with inter-moiré-band transitions obtained from an ab initio based continuum model. Transitions between the first and second moiré band for a twist angle of about 8° are reported and between the first and the third, and higher bands for a twist of about 3°. The signatures from IMBE for the latter highlight a strong departure from parabolic bands with flat minibands exhibiting very high density of states in accord with theory. These observations allow one to quantify the transition energies at the K point where the states relevant for correlation physics are hosted.