Programme

P.71 -- Posters, VCTP-50

Date: Thursday, 7 August 2025

Time: 08:30 - 10:00

IMPACT OF LASER PARAMETERS ON PHOTOISOMERIZATION PROBABILITY IN HYDROGEN CYANIDE

Le Viet Nam (1), Trieu Doan An (2), Phan Thi Ngoc Loan (1)

(1) Department of Physics, Ho Chi Minh City University of Education, Ho Chi Minh City, Vietnam; (2) Institute of Fundamental and Applied Sciences, Duy Tan University, Ho Chi Minh City, Vietnam

Laser-driven control of the isomerization process of the hydrogen cyanide (HCN) molecule has attracted attention due to its potential to enhance the formation yield of HNC isomer. Previous studies showed that two-color lasers – combinations of two lasers with different frequencies, can significantly enhance the isomerization probability compared with one-color laser. However, the influence of individual laser parameters remains insufficiently explored. In this study, we extend the investigation to clarify the influence of various laser parameters on the isomerization probability. Specifically, we examine the effects of intensity, pulse duration, and direction of laser polarization for one-color laser, and of intensity and relative phase for two-color lasers. To simulate the interaction of the HCN molecule with a laser field, we firstly calculate the potential energy surface (PES) using the Complete Active Space Self-Consistent Field method via the ORCA program. The isomerism process is simulated by numerically solving the time-dependent Schrödinger equation for the motion of hydrogen nucleus in the effective potential of PES and laser-molecular dipole coupling. The results reveal the specific regions of laser parameters for optimizing the isomerization probability. Remarkably, in high-probability cases, we observe the tunneling and interference effects in the nuclear wavefunction. The project is ongoing with indication of these effects in measurable signals.

Presenter: Lê Viết Nam