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arXiv · 1811.08830

On the identity of the identity operator in nonadiabatic linearized semiclassical dynamics

Maximilian A. C. Saller·Aaron Kelly·Jeremy O. Richardson
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Abstract

Simulating the nonadiabatic dynamics of condensed-phase systems continues to pose a significant challenge for quantum dynamics methods. Approaches based on sampling classical trajectories within the mapping formalism, such as the linearized semiclassical initial value representation (LSC-IVR), can be used to approximate quantum correlation functions in dissipative environments. Such semiclassical methods however commonly fail in quantitatively predicting the electronic-state populations in the long-time limit. Here we present a suggestion to minimize this difficulty by splitting the problem into two parts, one of which involves the identity, and treating this operator by quantum-mechanical principles rather than with classical approximations. This strategy is applied to numerical simulations of spin-boson model systems, showing its potential to drastically improve the performance of LSC-IVR and related methods with no change to the equations of motion or the algorithm in general, but rather by simply using different functional forms of the observables.

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Maximilian A. C. Saller, Aaron Kelly, Jeremy O. Richardson. 2018-11-21. On the identity of the identity operator in nonadiabatic linearized semiclassical dynamics. https://doi.org/10.1063/1.5082596

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