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arXiv · 0901.2943

Ground state energy of the two-dimensional weakly interacting Bose gas: First correction beyond Bogoliubov theory

Christophe Mora·Yvan Castin
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Abstract

We consider the grand potential $Ω$ of a two-dimensional weakly interacting homogeneous Bose gas at zero temperature. Building on a number-conserving Bogoliubov method for a lattice model in the grand canonical ensemble, we calculate the next order term as compared to the Bogoliubov prediction, in a systematic expansion of $Ω$ in powers of the parameter measuring the weakness of the interaction. Our prediction is in very good agreement with recent Monte Carlo calculations.

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Christophe Mora, Yvan Castin. 2009-05-16. Ground state energy of the two-dimensional weakly interacting Bose gas: First correction beyond Bogoliubov theory. https://doi.org/10.1103/physrevlett.102.180404

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