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arXiv · 2103.02586

Temperature Controlled Open Quantum System Dynamics using Time-dependent Variational Method

Mantas Jakučionis·Darius Abramavičius
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Abstract

Dirac-Frenkel variational method with Davydov D2 trial wavefunction is extended by introducing a thermalization algorithm and applied to simulate dynamics of a general open quantum system. The algorithm allows to control temperature variations of a harmonic finite size bath, when in contact with the quantum system. Thermalization of the bath vibrational modes is realised via stochastic scatterings, implemented as a discrete-time Bernoulli process with Poisson statistics. It controls bath temperature by steering vibrational modes' evolution towards their canonical thermal equilibrium. Numerical analysis of the exciton relaxation dynamics in a small molecular cluster reveals that thermalization additionally provides significant calculation speed up due to reduced number of vibrational modes needed to obtain the convergence.

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Mantas Jakučionis, Darius Abramavičius. 2021-03-03. Temperature Controlled Open Quantum System Dynamics using Time-dependent Variational Method. https://doi.org/10.1103/physreva.103.032202

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