Local phase space control and interplay of classical and quantum effects in dissociation of a driven Morse oscillator

Sethi, Astha; Keshavamurthy, Srihari

doi:10.1103/physreva.79.033416

Cited by 23 publications

(26 citation statements)

References 106 publications

(120 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Given that the key phase space structures regulating the dissociation dynamics have been identified, is it indeed possible to design control schemes by interfering with the specific phase space structures? Such a local phase space approach towards control has been explored recently for systems with lower degrees of freedom [72,73]. It remains to be seen if the insights gained from the current work can be utilized for controlling the dissociation dynamics by locally rebuilding appropriate phase space barriers.…”

mentioning

confidence: 98%

Driven coupled Morse oscillators: visualizing the phase space and characterizing the transport

Sethi

Keshavamurthy

2012

Molecular Physics

Self Cite

View full text Add to dashboard Cite

Recent experimental and theoretical studies indicate that intramolecular energy redistribution (IVR) is nonstatistical on intermediate timescales even in fairly large molecules. Therefore, it is interesting to revisit the the old topic of IVR versus quantum control and one expects that a classicalquantum perspective is appropriate to gain valuable insights into the issue. However, understanding classical phase space transport in driven systems is a prerequisite for such a correspondence based approach and is a challenging task for systems with more then two degrees of freedom. In this work we undertake a detailed study of the classical dynamics of a minimal model system -two kinetically coupled coupled Morse oscillators in the presence of a monochromatic laser field. Using the technique of wavelet transforms a representation of the high dimensional phase space, the resonance network or Arnold web, is constructed and analysed. The key structures in phase space which regulate the dissociation dynamics are identified. Furthermore, we show that the web is nonuniform with the classical dynamics exhibiting extensive stickiness, resulting in anomalous transport. Our work also shows that pairwise irrational barriers might be crucial even in higher dimensional systems.

show abstract

mentioning

confidence: 98%

Driven coupled Morse oscillators: visualizing the phase space and characterizing the transport

Sethi

Keshavamurthy

2012

Molecular Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…One possible route for such driving is the perturbation of the underlying potential energy surface by time-dependent, external fields. [1][2][3][4][5][6][7][8] The configurational change of the reactive system is typically mediated by an energy barrier separating reactant and product basins which must be somehow affected by the external control mechanism. In the limit of no driving, transition state theory (TST) [9][10][11][12][13][14][15][16][17][18][19][20][21] provides a powerful, though usually approximate, framework to calculate the rate from the reactive flux though the dividing surface (DS) separating the reactant and product regions.…”

Section: Introductionmentioning

confidence: 99%

Chemical dynamics between wells across a time-dependent barrier: Self-similarity in the Lagrangian descriptor and reactive basins

Junginger

Duvenbeck

Feldmaier

et al. 2017

The Journal of Chemical Physics

View full text Add to dashboard Cite

In chemical or physical reaction dynamics, it is essential to distinguish precisely between reactants and products for all time. This task is especially demanding in time-dependent or driven systems because therein the dividing surface (DS) between these states often exhibits a nontrivial time-dependence. The so-called transition state (TS) trajectory has been seen to define a DS which is free of recrossings in a large number of one-dimensional reactions across time-dependent barriers, and, thus, allows one to determine exact reaction rates. A fundamental challenge to applying this method is the construction of the TS trajectory itself. The minimization of Lagrangian descriptors (LDs) provides a general and powerful scheme to obtain that trajectory even when perturbation theory fails. Both approaches encounter possible breakdowns when the overall potential is bounded, admitting the possibility of returns to the barrier long after trajectories have reached the product or reactant wells. Such global dynamics cannot be captured by perturbation theory. Meanwhile, in the LD-DS approach, it leads to the emergence of additional local minima which make it difficult to extract the optimal branch associated with the desired TS trajectory. In this work, we illustrate this behavior for a time-dependent double-well potential revealing a self-similar structure of the LD, and we demonstrate how the reflections and side-minima can be addressed by an appropriate modification of the LD associated with the direct rate across the barrier.

show abstract

“…The external control of reactions [1][2][3][4][5][6][7] is increasingly a focus in the chemical sciences because novel products, synthesized at improved yields and selectivity, are needed for advanced industrial applications. Catalysts are often used to accelerate reaction rates and increase the efficiency of industrial processes in favor to undesired products.…”

Section: Introductionmentioning

confidence: 99%

Transition state theory for activated systems with driven anharmonic barriers

Revuelta

Craven

Bartsch

et al. 2017

The Journal of Chemical Physics

View full text Add to dashboard Cite

Classical transition state theory has been extended to address chemical reactions across barriers that are driven and anharmonic. This resolves a challenge to the naive theory that necessarily leads to recrossings and approximate rates because it relies on a fixed dividing surface. We develop both perturbative and numerical methods for the computation of a time-dependent recrossing-free dividing surface for a model anharmonic system in a solvated environment that interacts strongly with an oscillatory external field. We extend our previous work, which relied either on a harmonic approximation or on periodic force driving. We demonstrate that the reaction rate, expressed as the long-time flux of reactive trajectories, can be extracted directly from the stability exponents, namely, Lyapunov exponents, of the moving dividing surface. Comparison to numerical results demonstrates the accuracy and robustness of this approach for the computation of optimal (recrossing-free) dividing surfaces and reaction rates in systems with Markovian solvation forces. The resulting reaction rates are in strong agreement with those determined from the long-time flux of reactive trajectories.

show abstract

Local phase space control and interplay of classical and quantum effects in dissociation of a driven Morse oscillator

Cited by 23 publications

References 106 publications

Driven coupled Morse oscillators: visualizing the phase space and characterizing the transport

Driven coupled Morse oscillators: visualizing the phase space and characterizing the transport

Chemical dynamics between wells across a time-dependent barrier: Self-similarity in the Lagrangian descriptor and reactive basins

Transition state theory for activated systems with driven anharmonic barriers

Contact Info

Product

Resources

About