Year: 2025
Type: article
Abstract: Two-dimensional hexagonal materials such as transition metal dichalcogenides exhibit valley degrees of freedom, offering fascinating potential for valley-based quantum computing and optoelectronics. In nonlinear optics, the K and K’ valleys provide excitation resonances that can be used for ultrafast control of excitons, Bloch oscillations, and Floquet physics. Under intense laser fields, however, the role of coherent carrier dynamics away from the K/K’ valleys is largely unexplored. In this study, we observe quantum interferences in high harmonic generation from monolayer WS2 as laser fields drive electrons from the valleys across the full Brillouin zone. In the perturbative regime, interband resonances at the valleys enhance high harmonic generation through multi-photon excitations. In the strong-field regime, the high harmonic generation is sensitively controlled by quantum interferences of laser-field-driven electrons occupying various points in the Brillouin zone, including regions far from the K/K’ valleys. Our experimental observations are in strong agreement with quantum simulations, validating their interpretation. This work proposes new routes for harnessing laser-driven quantum interference in two-dimensional hexagonal systems and all-optical techniques to occupy and read-out electronic structures in the full Brillouin zone via strong-field nonlinear optics, advancing quantum technologies. Here, the authors demonstrate that intense laser pulses drive electrons across the full Brillouin zone in monolayer WS2, producing quantum interferences that control high harmonic generation.
Source: Nature Communications
Institutions: Pohang University of Science and Technology, Institute for Basic Science, Graz University of Technology, Max Planck Institute for the Structure and Dynamics of Matter, Universidad de Panamá, Universidad Autónoma de Chiriquí, Nanyang Technological University, National Institute for Materials Science, Technion – Israel Institute of Technology
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $6,990
Funders: Flatiron Health, National Research Foundation, Deutsche Forschungsgemeinschaft, Ministry of Education, Culture, Sports, Science and Technology, Austrian Science Fund, National Research Foundation of Korea, Ministry of Education, India, Bộ Giáo dục và Ðào tạo, Iran Telecommunication Research Center, Institute for Basic Science, Ministry of Science and ICT, South Korea, Japan Society for the Promotion of Science, Institute for Information and Communications Technology Promotion, Core Research for Evolutional Science and Technology, H2020 European Research Council
Awards: G1418483613, G1890223652, G213344254, G2442584775, G267083200, G2985547930, G3136449320, G3665828761, G3953512425, G4091144171, G4162329948, G4700831490, G4806815962, G5099004511, Transition-metal dichalcogenides in and out of equilibrium, G6718509927, Quantum Spectroscopy: exploring new states of matter out of equilibrium, G7486974924, G7879866177, SFB 925: Lichtinduzierte Dynamik und Kontrolle korrelierter Quantensysteme, G8590477180, G898758523
OpenAlex ID: W4415964330