Research Interest
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
Postdoctoral Work:
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.
Project-1:
We will investigate the photo-induced coupled electronic-nuclear quantum dynamics of norbornadiene. The photoexcitation of norbornadiene leads to two different reaction channels, a photoisomerization to quadricyclane through a [2+2] 4C ring closure and a fragmentation via a [4+2] Retro-Diels–Alder cycloreversion yielding cyclopentadiene and acetylene. We will design control schemes based on selective excitation of specific electronic coherences by tuning the parameters of short 1-3 fs UV or IR optical pulses to favor one or the other channel. The role of entanglement between nuclear and electronic degrees of freedom for controlling the dynamics will be investigated. In industrial applicability, a controlled photo-induced reaction of norbornadine would be advantageous for energy storage materials.
Experimental Collaborator: Prof. Dr. FRANCESCA CALEGARI, Center for Free-Electron Laser Science (CFEL) Deutsches Elektronen-Synchrotron DESY, University of Hamburg, Germany
Project-2:
The Jahn-Teller (JT) effect, a pivotal occurrence in nonlinear molecular systems featuring degenerate electronic configurations, serves as a fundamental mechanism for ultrafast geometric relaxation. Such ultrafast intramolecular relaxation dynamics of photoexcited molecules are of fundamental photochemical interest. The methane cation (CH4+ / CD4+ ) stands as a classic system showcasing JT distortions. Here, we are working on the quantum dynamical study on the three lowest states of CD4+ upon sudden ionization using an XUV attopulse for two nuclear coordinates that describe the structural rearrangement.
Experimental Collaborator: Prof. Dr. Giuseppe Sansone, Attosecond- and Strong Field Physics at the Institute of Physics, Universität Freiburg, Germany
Ph. D Work:
In my Ph.D., I worked on the coupled electron and nuclear dynamics of small, one and two-electron molecular systems ( HD+ , H2+ , H2 ) in strong laser fields. I mainly studied the dissociative ionization reaction processes and the effect of the Carrier-Envelope Phase (CEP) of ultrashort laser pulses on these processes. I used both classical and quantum mechanical methods to study the dynamics. In the classical trajectory Monte Carlo (CTMC) method, I have used the Hamiltonian formalism of the classical mechanics and solved the coupled Hamilton’s equation of motion for the dynamics in the presence of the laser field. In the Quantum dynamics time dependent Schrödinger equation (TDSE) is solved by applying the split-operator method. The initial wavepacket is constructed by multiplying the vibrational bound state and the ground electronic state. Bound states are calculated by the Fourier-Grid Hamiltonian method, and the ground electronic state is calculated by imaginary time propagation.
