Abstract
Two-center interference for heteronuclear diatomic molecules (HeDM) is investigated. The minimum in the high-order harmonic spectrum, as a consequence of the destructive interference, is shifted to lower harmonic orders compared with that in a homonuclear case. This phenomenon is explained by performing phase analysis. It is found that, for an HeDM, the high harmonic spectrum contains information not only on the internuclear separation but also on the properties of the two separate centers, which implies the potential application of estimating the asymmetry of molecules and judging the linear combination of atomic orbitals (LCAO) for the highest occupied molecular orbital (HOMO). Moreover, the possibility to monitor the evolution of HOMO itself in molecular dynamics is also promised.
Highlights
When atoms and molecules are exposed to intense laser irradiation, high-order harmonics are generated
Our study indicates that the two-center interference offers opportunities to estimate the asymmetry of the objective heteronuclear diatomic molecules (HeDM) and to judge the linear combination of diatomic orbital (LCAO) for molecular orbitals
Phase analysis is performed to explain this phenomenon. It shows that the shift results from the additional recombining phase difference, which pushes the position where the value of total phase difference equals π to lower harmonic orders
Summary
When atoms and molecules are exposed to intense laser irradiation, high-order harmonics are generated. Lein et al have predicted the minima of H2 and H+2 theoretically by numerically solving the time-dependent Schrodinger equation (TDSE) [12, 13] They demonstrate that this kind of intensity independent minimum, which is named structural minimum, is a consequence of the interference between the emissions from the two centers, when the de Broglie wavelength of the returning electron, the internuclear distance R and alignment angle θ satisfy the relationship Rcos θ =(2m+1)λ /2. Researches on the two-center interference mainly focus on homonuclear diatomic molecule (HoDM), such as H2, N2, O2, or some other simple molecules with symmetric HOMOs like CO2 [19,20,21,22,23] Minima from those symmetric molecules are just dependent on internuclear distances and alignment angles, while little information on the combining atoms is included. The possibility to monitor the evolution of the HOMO itself in molecular dynamics is promised
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