Dresden 2026 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 8: Ultra-fast Phenomena I
HL 8.3: Talk
Monday, March 9, 2026, 15:30–15:45, POT/0006
Ultrafast excitonic coherent oscillations in monolayer tungsten disulphide — •Jorge Cervantes Villanueva1, Davide Sangalli2, Alberto García-Cristóbal1, and Alejandro Molina-Sánchez1 — 1Institut de Ciència dels Materials (ICMUV), Universitat de València, Catedrático José Beltrán 2, 46980 Paterna, Valencia, Spain — 2Istituto di Struttura della Materia-CNR (ISM-CNR), Area della Ricerca di Roma 1, Monterotondo Scalo, Italy
Understanding coherent excitonic dynamics in two-dimensional semiconductors is crucial for advancing quantum-optical technologies. Monolayer transition metal dichalcogenides (TMDs) provide an ideal platform due to their strong Coulomb interactions and large exciton binding energies. We perform ab initio pump-probe simulations by propagating the time-dependent density matrix under the influence of overlapping pump and probe fields, capturing the generation and detection of coherent excitons on femtosecond timescales. Focusing on monolayer WS2 with a pump tuned between the A and B excitons, we observe ultrafast oscillations arising from coherent coupling among multiple excitonic states, including the intermediate A* resonance. Exploiting the balance between exciton populations, we propose a scheme to control the coherent response, realizing an optical switch with potential applications in quantum information. These results establish ab initio pump-probe modeling as a predictive tool for characterizing and manipulating coherent excitonic states.
Keywords: Coherent excitons; Ultrafast spectroscopy; Pump-probe; 2D material; Rabi oscillations