We investigate the influence of the field fluctuations to the emission photons of V-type three-level systems.The emission intensity I and Mandel's Q parameter show stochastic resonance with respect to the pure dephasing constantγp.The amplitude fluctuation of the field causes these systems to lose their coherence.On the other hand,the amplitude fluctuation provides a new interference method for these systems.The quantum beats are shown in the orthogonal system.
We study the two coupling two-level single molecules driven by an external field as a photon pair source. The probability of emitting two photons, P2, is employed to describe the photon pair source quality in a short time, and the correlation coefficient RAB is employed to describe the photon pair source quality in a long time limit. The results demonstrate that the coupling single quantum emitters can be considered as a stable photon pair source.
We have carried out a quasi-classical trajectory calculation for the reaction of Ne + H + 2 (ν=0,j=1) → NeH + + H on the ground state (1 2 A) using the LZHH potential energy surface constructed by L et al.[L S J,Zhang P Y,Han K L and He G Z 2010 J.Chem.Phys.132 014303].Differential cross sections at many collision energies indicate that the reaction is dominated by forward-scattering.In addition,the NeH + product shows rotationally hot and vibrationally cold distributions.Stereodynamical results indicate that the products are strongly polarized in the direction perpendicular to the scattering plane and that the products rotate mainly in planes parallel to the scattering plane.
The quasi-classical trajectory（QCT） method is used to study the H+HS reaction on a newly built potential energy surface（PES） of the triplet state of H2S（3A″） in a collision energy range of 0-60 kcal/mol.Both scalar properties, such as the reaction probability and the integral cross section（ICS）,and the vector properties,such as the angular distribution between the relative velocity vector of the reactant and that of the product,etc.,are investigated using the QCT method.It is found that the ICSs obtained by the QCT method and the quantum mechanical（QM） method accord well with each other.In addition,the distribution for the product vibrational states is cold,while that for the product rotational states is hot for both reaction channels in the whole energy range studied here.
In this work, we propose an algebraic recursion method to study the dynamical evolution of the two-site Bose–Hubbard model. We analyze its properties from the viewpoints of single partite purity, energy, and trace distance, in which the model is considered as a typical bipartite system. The analytical expressions for the quantities are derived. We show that the purity can well reflect the transition between different regimes for the system. In addition, we demonstrate that the transition from the delocalization regime to the self-trapping regime with the ratio η increasing not only happens for an initially local state but also for any initial states. Furthermore, we confirm that the dynamics of the system presents a periodicity for η = 0 and the period is tc = π/2J when the initial state is symmetric.
