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Broad Areas:
Attochemistry
Coupled electron-nuclear dynamics in molecules from femtosecond to attosecond time scale
Quantum and Classical Dynamics of Atoms and Molecules in Ultra-short Intense Laser Field
Excited State Quantum Chemistry Calculations
Strong field ionization and dissociation dynamics of molecules
Currently, I am working in the field of attosecond science. Attochemistry is made possible through the engineering of short, few femtoseconds (fs) and attosecond (as) optical pulses which allow pumping and probing the motions of electrons and nuclei in molecular systems on their intrinsic time scales with unprecedented time resolution.
Ultrafast photoionization prepares coherent superpositions of electronic states that drive coupled electron–nuclear dynamics in CH₄⁺ near nonadiabatic seams. Using fully quantum vibronic dynamics, we show that the force exerted by electrons on nuclei remains highly local in coordinate space, even in the presence of strong nonadiabatic coupling. By decomposing the total vibronic force into population-driven and coherence-driven contributions, we identify how ultrashort-pulse-induced electronic coherences actively steer structural rearrangement through Jahn–Teller distortions. The work establishes a direct connection between attosecond electronic coherence and the emergence of nonclassical nuclear forces governing ultrafast molecular dynamics.
We investigate the ultrafast photodissociation dynamics of CH₄ and CD₄ driven by a two-color near-infrared (NIR) and attosecond pulse train (APT) scheme. In this approach, the NIR pulse first prepares vibrationally excited neutral molecules, which are subsequently ionized by the delayed APT to launch coherent cationic wave packets. By varying the IR–APT delay, we explore how electronic coherence and nuclear motion control dissociation yields, isotope effects, and nonadiabatic dynamics on attosecond-to-femtosecond timescales.
We investigate how ultrafast photoexcitation creates entanglement between molecular orientation and vibronic degrees of freedom in an ensemble of initially randomly oriented LiH molecules. Using fully quantum dynamical simulations, we show that a small number of principal orientations and vibronic modes dominate the coherent dynamics induced by ultrashort laser pulses. The work reveals how electronic coherences drive charge migration and nuclear motion, and how the degree of entanglement can be tuned through pulse parameters and excitation pathways. These results provide new insight into coherent control and attosecond dynamics in molecular ensembles.
We developed and benchmarked fully quantum and quasi-classical approaches to investigate coupled electron–nuclear dynamics in H2+ driven by intense few-cycle laser pulses. The study reveals how ionization, dissociation, and carrier-envelope-phase (CEP)-dependent electron localization emerge from the interplay between ultrafast electronic motion and slower nuclear dynamics. By directly comparing wave packet propagation with trajectory-based classical dynamics under identical initial conditions, we identify the regimes where classical descriptions reproduce strong-field quantum behavior and where distinctly quantum effects dominate. This work provides fundamental insight into attosecond-scale molecular dynamics and the control of chemical processes in strong laser fields.
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