Stochastic excitation and dissociation of adsorbate in a laser field

Wu, Binruo; Liu, Wing‐Ki

doi:10.1016/0378-4371(94)90524-x

Cited by 6 publications

(5 citation statements)

References 18 publications

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“…The field intensity leading to this onset is in fact the threshold field for ionization or dissociation, and can be predicted by the resonance overlapping criterion of Chiricov which has been applied for both Coulomb and Morse potentials with more or less successful results. 15,17,26 The addition of a second driving field with frequency 2 induces an additional series of nonlinear resonances at energies satisfying the relationship…”

Section: Phase Space Origins Of Stabilization and Of Relative Phamentioning

confidence: 99%

“…14,[16][17][18] The main concern in those studies was to find the field parameters for which the addition of the second laser enhances the dissociation process, thereby lowering the required field intensity for the occurence of dissociation. In phase space terms, the key idea is the following: by properly tuning the second frequency, one aims at interspersing the nonlinear resonances of the second field together with their chaotic layers between the resonances of the first laser.…”

Section: Introductionmentioning

confidence: 99%

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Stabilization and relative phase effects in a dichromatically driven diatomic Morse molecule: Interpretation based on nonlinear classical dynamics

Constantoudis

Nicolaides

2005

The Journal of Chemical Physics

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The dissociation dynamics of a dichromatically laser-driven diatomic Morse molecule vibrating in the ground state is investigated by applying tools of the nonlinear theory of classical Hamiltonian systems. Emphasis is placed on the role of the relative phase of the two fields, . First, it is found that, just like in quantum mechanics, there is dependence of the dissociation probability on . Then, it is demonstrated that addition of the second laser leads to suppression of probability ͑stabilization͒, when the intensity of the first laser is kept constant just above or below the single laser dissociation threshold. This "chemical bond hardening" diminishes as increases. These effects are investigated and interpreted in terms of modifications in phase space topology. Variations of as well as of the intensity of the second laser may cause ͑i͒ appearance/disappearance of the stability island corresponding to the common resonance with the lowest energy and ͑ii͒ deformation and movement of the region of Kolmogorov-Arnold-Moser tori that survive from the undriven system. The latter is the main origin in phase space of stabilization and dependence. Finally, it is shown that the use of short laser pulses enhances both effects.

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Section: Phase Space Origins Of Stabilization and Of Relative Phamentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Stabilization and relative phase effects in a dichromatically driven diatomic Morse molecule: Interpretation based on nonlinear classical dynamics

Constantoudis

Nicolaides

2005

The Journal of Chemical Physics

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“…The two-color laser-driven dissociation of molecules is also of great interest to researchers because these seemingly simple systems display complex dynamics and behavior that single component laser field cannot exhibit [1,2,3,4,5,6,7,8,9]. The theoretical literature on laser-driven dissociation of molecules has been extensive in the past three decades [3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]. Among these is Ref.…”

Section: Introductionmentioning

confidence: 99%

Bifurcations as dissociation mechanism in bichromatically driven diatomic molecules

Huang

Chandre

Uzer

2008

The Journal of Chemical Physics

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We discuss the influence of periodic orbits on the dissociation of a model diatomic molecule driven by a strong bichromatic laser fields. Through the stability of periodic orbits, we analyze the dissociation probability when parameters, such as the two amplitudes and the phase lag between the laser fields, are varied. We find that qualitative features of dissociation can be reproduced by considering a small set of short periodic orbits. The good agreement with direct simulations demonstrates the importance of bifurcations of short periodic orbits in the dissociation dynamics of diatomic molecules.

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“…When the oscillator is subjected to an external driving field, a particle in the bound region can escape to the unbound region and this transition corresponds to the dissociation of the molecule. The dissociation occurs through chaotic routes, * eflima@rc.unesp.br † tarciusnramos@gmail.com ‡ regydio@rc.unesp.br as a result of the destruction of Kolmogorov-Arnold-Moser (KAM) tori in phase-space for increasing values of the field amplitude [3,20].Several works have investigated the classical dissociation dynamics within the driven Morse model [1][2][3][4][5][6][7][8][9][10][11][12][21][22][23][24][25][26]. Also, many quantum-classical comparisons have been performed and correspondences between the two theories have been found in some situations [27][28][29][30][31][32][33][34][35][36][37].…”

mentioning

confidence: 99%

“…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. The classical driven Morse oscillator has been extensively applied to the study of the dissociation dynamics of heterodiatomic molecules by means of infrared laser fields [1][2][3][4][5][6][7][8][9][10][11][12]. The interaction between the molecule and the laser field is commonly given by the product of a time-dependent external field, which accounts for the electric field of the laser, with a position-dependent function, associated with the permanent dipole moment of the molecule.…”

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confidence: 99%

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

2013

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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. The classical driven Morse oscillator has been extensively applied to the study of the dissociation dynamics of heterodiatomic molecules by means of infrared laser fields [1][2][3][4][5][6][7][8][9][10][11][12]. The interaction between the molecule and the laser field is commonly given by the product of a time-dependent external field, which accounts for the electric field of the laser, with a position-dependent function, associated with the permanent dipole moment of the molecule. Consequently, the dissociation dynamics depends on both the external field and the dipole function. Understanding the role of the dipole function in the dynamics of the Morse oscillator can help to gain physical insights on the dissociation dynamics of diatomic molecules.The concept of a dipole function for a diatomic molecule arises within the Born-Oppenheimer picture [13][14][15]. In this picture, the electronic wavefunction depends parametrically on the internuclear distance for a given molecular state. The dipole moment of the molecular charge distribution can be represented by a function of the internuclear distance. Diatomic molecules possess many forms of dipole functions [16][17][18][19], which typically go asymptotically to zero for large internuclear distances. Correspondingly, one can associate an effective spatial range with a dipole function.The free Morse oscillator has two distinct energy regions. A particle placed in the bound region performs oscillatory motion, which represents the vibration of the molecule. A particle placed in the unbound region escapes to infinity and this sc...

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Stochastic excitation and dissociation of adsorbate in a laser field

Cited by 6 publications

References 18 publications

Stabilization and relative phase effects in a dichromatically driven diatomic Morse molecule: Interpretation based on nonlinear classical dynamics

Stabilization and relative phase effects in a dichromatically driven diatomic Morse molecule: Interpretation based on nonlinear classical dynamics

Bifurcations as dissociation mechanism in bichromatically driven diatomic molecules

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

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