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arXiv · 0910.0720

Ultracold atoms at unitarity within quantum Monte Carlo

Andrew J. Morris·P. Lopez Rios·R. J. Needs
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Abstract

Variational and diffusion quantum Monte Carlo (VMC and DMC) calculations of the properties of the zero-temperature fermionic gas at unitarity are reported. The ratio of the energy of the interacting to the non-interacting gas for a system of 128 particles is calculated to be 0.4517(3) in VMC and 0.4339(1) in the more accurate DMC method. The spherically-averaged pair-correlation functions, momentum densities, and one-body density matrices are very similar in VMC and DMC, but the two-body density matrices and condensate fractions show some differences. Our best estimate of the condensate fraction of 0.51 is a little smaller than values from other quantum Monte Carlo calculations.

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Andrew J. Morris, P. Lopez Rios, R. J. Needs. 2009-10-05. Ultracold atoms at unitarity within quantum Monte Carlo. https://doi.org/10.1103/physreva.81.033619

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