Non-perturbative method to compute thermal correlations in one-dimensional systems

Autor: Beck, Stefan, Mazets, Igor E., Schweigler, Thomas
Rok vydání: 2018
Předmět:
Zdroj: Phys. Rev. A 98, 023613 (2018)
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevA.98.023613
Popis: We develop a highly efficient method to numerically simulate thermal fluctuations and correlations in non-relativistic continuous bosonic one-dimensional systems. The method is suitable for arbitrary local interactions as long as the system remains dynamically stable. We start by proving the equivalence of describing the systems through the transfer matrix formalism and a Fokker-Planck equation for a distribution evolving in space. The Fokker-Planck equation is known to be equivalent to a stochastic differential (It\={o}) equation. The latter is very suitable for computer simulations, allowing the calculation of any desired correlation function. As an illustration, we apply our method to the case of two tunnel-coupled quasi-condensates of bosonic atoms. The results are compared to the predictions of the sine-Gordon model for which we develop analytic expressions directly from the transfer matrix formalism.
Comment: Version that was accepted by Phys. Rev. A. arXiv admin note: substantial text overlap with arXiv:1712.01190
Databáze: arXiv