Programme

O.40 -- Oral, VCTP-51

Date: Thursday, 6 August 2026

Time: 15:20 - 15:40

TERAHERZT-INDUCED FREQUENCY SHIFT OF HIGH-HARMONIC GENERATION IN TRANSITION METAL DICHALCOGENIDE MONOLAYERS

Duong D. Hoang-Trong (1,2), Trong-Thanh D. Nguyen (3), Doan-An Trieu (4,5), Cong Ngo (3), Cam-Tu Le (6,7), Le Minh Chau (8), Huynh Thanh Duc (9), Lan Nguyen Tran (10,11), Van-Hoang Le (3), and Ngoc-Loan Phan (3,*)

(1) Simulation in Materials Science Research Group, Science and Technology Advanced Institute, Van Lang University, Ho Chi Minh City, Vietnam (2) Faculty of Applied Technology, School of Technology, Van Lang University, Ho Chi Minh City, Vietnam (3) Ho Chi Minh City University of Education, 280 An Duong Vuong Street, Ward 4, District 5, Ho Chi Minh City 72711, Vietnam (4) Institute of Fundamental and Applied Sciences, Duy Tan University, Ho Chi Minh City 700000, Vietnam (5) Faculty of Natural Sciences, Duy Tan University, Da Nang City 550000, Vietnam (6) Atomic Molecular and Optical Physics Research Group, Institute for Advanced Study in Technology, Ton Duc Thang University, Ho Chi Minh City 72912, Vietnam (7) Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City 72912, Vietnam (8) Institute of Applied Mechanics and Informatics, Vietnam Academy of Science and Technology, Vietnam (9) Ho Chi Minh City Institute of Physics, Vietnam Academy of Science and Technology, 1 Mac Dinh Chi Street, District 1, Ho Chi Minh City, Vietnam (10) University of Science, Vietnam National University, Ho Chi Minh City 70000, Vietnam (11) Vietnam National University, Ho Chi Minh City 70000, Vietnam *Author to whom correspondence should be addressed: loanptn@hmue.edu.vn

High-harmonic generation (HHG) in transition metal dichalcogenides (TMDCs) has emerged as a powerful tool for probing ultrafast electron dynamics, with microscopic properties directly encoded in the harmonic signals [1,2]. Here, we investigate HHG in two-dimensional MoS₂ driven by an intense laser pulse in the presence of an additional Terahertz (THz) field. By solving the Semiconductor Bloch Equations (SBE) [3], we find that the THz pulse induces a frequency shift in the HHG spectra, which depends on the THz field strength, harmonic energy and driving laser parameters. To elucidate the underlying mechanism, we apply a classical Strong Field Approximation (SFA) [4] and find excellent qualitative agreement with the SBE results. The project is still going on with applying SFA to construct a simple analytical model to explain the shift law for wide range of harmonic energy and driving laser parameters. Our findings suggest a promising route toward coherent control of solid-state high harmonics in two-dimensional quantum materials. Keywords: High-Order Harmonic Generation, Transition Metal Dichalcogenide Monolayers, THz Field, Strong-Field Approximation, High-harmonic frequency shift.

Presenter: Nguyen Dang Trong Thanh