Abstract
The partition of the photon energy into the subsystems of molecules determines many photon-induced chemical and physical dynamics in laser-molecule interactions. The electron-nuclear energy sharing from multiphoton ionization of molecules has been used to uncover the correlated dynamics of the electron and fragments. However, most previous studies focus on symmetric molecules. Here we study the electron-nuclear energy sharing in strong-field photoionization of HeH2+ by solving the one-dimensional time-dependent Schrödinger equation (TDSE). Compared with symmetric molecules, the joint electron-nuclear energy spectrum (JES) of HeH2+ reveals an anomalous energy shift at certain nuclear energies, while it disappears at higher and lower nuclear energies. Through tracing the time evolution of the wavepacket of bound states, we identify that this energy shift originates from the joint effect of the Stark shift, associated with the permanent dipole, and the Autler-Townes effect due to the coupling of the 2pσ and 2sσ states in strong fields. The energy shift in the JES appears at certain nuclear distances only when both Stark effect and Autler-Townes effect play important roles. We further demonstrate that the electron-nuclei energy sharing can be controlled by varying laser intensity for asymmetric molecules, providing alternative approaches to manipulate photochemical reactions for more complex molecules.
Highlights
The partition of the photon energy into the subsystems of molecules determines many photon-induced chemical and physical dynamics in laser-molecule interactions
By tracing the time evolution of the electron wave packet of bound states, we identify that the energy shift originates from the joint effect of the Stark shift, which is associated with the permanent dipole of HeH2+ molecule, and the Autler-Townes effect induced by the coupling of the 2pσ and 2sσ states of HeH2+ in strong laser fields
It is important to emphasize that this energy shift in the joint electron-nuclear energy spectrum (JES) of the asymmetric HeH2+ is different from that of the symmetric H+2 21, where no energy shift is observed for low vibrational states
Summary
The partition of the photon energy into the subsystems of molecules determines many photon-induced chemical and physical dynamics in laser-molecule interactions. The electron-nuclear energy sharing from multiphoton ionization of molecules has been used to uncover the correlated dynamics of the electron and fragments. We study the electron-nuclear energy sharing in strong-field photoionization of HeH2+ by solving the onedimensional time-dependent Schrödinger equation (TDSE). The energy sharing between the electrons and the nuclei manifests itself as many diagonal maxima separated by the laser frequency, ω, in the JES of the electron Ee and the nuclear EN energies17 [atomic units (a.u.) are used unless stated otherwise], Ee = E0 + nω − UP − EN,. For symmetric H+2 molecule, the relation of equation (1) might not be satisfied for high vibrational state because of the strong coupling between the ground state and first excited state of molecule in strong laser fields at a large nuclear distance[21]. It is shown that equation (1) is satisfied for the JES of multielectron molecules CO and the JES depends strongly on the vibrational state[25,26]
Sign-in/Register to view highlights & summary 
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call