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arXiv:2407.18059 · Physical Review Research

Equation of state of Bose gases beyond the universal regime

Jordi Pera, Jordi Boronat

Published Dec 30, 2024• 1 citation
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Abstract

The equation of state of dilute Bose gases, in which the energy only depends on the s -wave scattering length, is rather unknown beyond the universal limit. We have carried out a set of diffusion Monte Carlo calculations up to gas parameters of 10 − 2 to explore how the departure from the universality emerges. Using different model potentials, we calculate the energies of the gas in an exact way, within some statistical noise, and report the results as a function of the three relevant scattering parameters: the s -wave scattering length a 0 , the s -wave effective range r 0 , and the p -wave scattering length a 1 . If the effective range is not large, we observe universality in terms of a 0 and r 0 up to gas parameters of 10 − 2 . If r 0 grows, the regime of universality in these two parameters is reduced and effects of a 1 start to be observed. In the ( a 0 , r 0 ) universal regime we propose an analytical law that reproduces fairly well the exact energies. Published by the American Physical Society 2024

DOI
10.1103/physrevresearch.6.l042071

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