The single ionization rate of the diatomic molecular ion H2^＋ with different active orbitals in an intense field is studied by using S-matrix theory. Our results show that the orientation-dependent single ionization probability of H2^＋ is greatly dependent on the symmetry and the electron density distribution of its initial states, and it can be used to identify the excited state of the molecular ion in the dissociation process.
The nonlinear Wannier functions in square Kronig-Penney potential are investigated with the help of a set of exact nonlinear Bloch solutions. The nonlinear interaction makes the Wannier functions fall off as non-exponential law with distance and enhances the tunneling coupling between the neighbor sites.
We theoretically analysed the linewidth of the probe absorption spectrum in a cold Cs atom-molecule system. The tunnelling coupling between the two excited molecular states, especially for the Cs atom molecule system, plays an important role in obtaining the sub-natural linewidth of the probe absorption spectrum. For example, when the tunnelling couple strength fulfils σ12=10γab1, the linewidth is only about 0.66 MHz. Moreover, since the linewidth of interest is dominated by the tunnelling coupling, the absorption peak becomes very narrow even in the case of large pump laser intensities.
