Role of the range of the dipole function in the classical dynamics of molecular dissociation

The dissociation dynamics of heteronuclear diatomic molecules induced by infrared laser pulses is investigated within the framework of the classical driven Morse oscillator. The interaction between the molecule and the laser field described in the dipole formulation is given by the product of a time...

Descripción completa

Detalles Bibliográficos
Autores: De Lima, Emanuel F. [UNESP], Ramos, Tárcius N. [UNESP], De Carvalho, R. Egydio [UNESP]
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2013
País:Brasil
Institución:Universidade Estadual Paulista (UNESP)
Repositorio:Repositório Institucional da UNESP
Idioma:inglés
OAI Identifier:oai:repositorio.unesp.br:11449/74344
Acceso en línea:http://dx.doi.org/10.1103/PhysRevE.87.014901
http://hdl.handle.net/11449/74344
Access Level:acceso abierto
Palabra clave:Angle variables
Carrier frequency
Chaotic regions
Classical dynamics
Dissociation dynamics
Dissociation probability
External fields
Fourier coefficients
Heteronuclear diatomic molecule
Heteronuclear molecules
Initial energy
Laser fields
Molecular dissociation
Morse oscillator
Nonlinear resonance
Numerical calculation
Permanent dipoles
Phase spaces
Thin layers
Time-dependent
Dynamics
Fourier analysis
Molecules
Phase space methods
Dissociation
Descripción
Sumario:The dissociation dynamics of heteronuclear diatomic molecules induced by infrared laser pulses is investigated within the framework of the classical driven Morse oscillator. The interaction between the molecule and the laser field described in the dipole formulation is given by the product of a time-dependent external field with a position-dependent permanent dipole function. The effects of changing the spatial range of the dipole function in the classical dissociation dynamics of large ensembles of trajectories are studied. Numerical calculations have been performed for distinct amplitudes and carrier frequencies of the external pulses and also for ensembles with different initial energies. It is found that there exist a set of values of the dipole range for which the dissociation probability can be completely suppressed. The dependence of the dissociation on the dipole range is explained through the examination of the Fourier series coefficients of the dipole function in the angle variable of the free system. In particular, the suppression of dissociation corresponds to dipole ranges for which the Fourier coefficients associated with nonlinear resonances are null and the chaotic region in the phase space is reduced to thin layers. In this context, it is shown that the suppression of dissociation of heteronuclear molecules for certain frequencies of the external field is a consequence of the finite range of the corresponding permanent dipole. © 2013 American Physical Society.