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Test of variational approximation for $phi^4$ quantum chain by Monte Carlo simulation

Wolfhard Janke·Tilman Sauer
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Abstract

We report results of a Monte Carlo simulation of the $ϕ^4$ quantum chain. In order to enhance the efficiency of the simulation we combine multigrid simulation techniques with a refined discretization scheme. The resulting accuracy of our data allows for a significant test of an analytical approximation based on a variational ansatz. While the variational approximation is well reproduced for a large range of parameters we find significant deviations for low temperatures and large couplings.

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Wolfhard Janke, Tilman Sauer. 1994-12-05. Test of variational approximation for $phi^4$ quantum chain by Monte Carlo simulation. https://doi.org/10.1016/s0375-9601(05)80013-1

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