External Source Method for Kubo-Transformed Quantum Correlation Functions

Atsushi Horikoshi

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arXiv · 1401.0983

External Source Method for Kubo-Transformed Quantum Correlation Functions

Atsushi Horikoshi

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Abstract

We revisit the external source method for Kubo-transformed quantum correlation functions recently proposed by Krishna and Voth. We derive an exact formula and show that the Krishna-Voth formula can be derived as an approximation of our formula. Some properties of this approximation are clarified through a model calculation of the position autocorrelation function for a one-dimensional harmonic oscillator. A key observation is that the Krishna-Voth correlation function has a term which behaves as the secular term in perturbation theory.

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Atsushi Horikoshi. 2014-01-06. External Source Method for Kubo-Transformed Quantum Correlation Functions. https://arxiv.org/abs/1401.0983

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