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arXiv · 1909.10418

A new approach for open quantum systems based on a phonon number representation of a harmonic oscillator bath

M. Tokieda·K. Hagino
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Abstract

To investigate a system coupled to a harmonic oscillator bath, we propose a new approach based on a phonon number representation of the bath. Compared to the method of the hierarchical equations of motion, the new approach is computationally much less expensive in a sense that a reduced density matrix is obtained by calculating the time evolution of vectors, instead of matrices, which enables one to deal with large dimensional systems. As a benchmark test, we consider a quantum damped harmonic oscillator, and show that the exact results can be well reproduced. In addition to the reduced density matrix, our approach also provides a link to the total wave function by introducing new boson operators.

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M. Tokieda, K. Hagino. 2019-09-23. A new approach for open quantum systems based on a phonon number representation of a harmonic oscillator bath. https://doi.org/10.1016/j.aop.2019.168005

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