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Quantum Monte Carlo study of quasi-one-dimensional Bose gases

G. E. Astrakharchik·D. Blume·S. Giorgini·B. E. Granger
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Abstract

We study the behavior of quasi-one-dimensional (quasi-1d) Bose gases by Monte Carlo techniques, i.e., by the variational Monte Carlo, the diffusion Monte Carlo, and the fixed-node diffusion Monte Carlo technique. Our calculations confirm and extend our results of an earlier study [Astrakharchik et al., cond-mat/0308585]. We find that a quasi-1d Bose gas i) is well described by a 1d model Hamiltonian with contact interactions and renormalized coupling constant; ii) reaches the Tonks-Girardeau regime for a critical value of the 3d scattering length a_3d; iii) enters a unitary regime for |a_3d| -> infinity, where the properties of the gas are independent of a_3d and are similar to those of a 1d gas of hard-rods; and iv) becomes unstable against cluster formation for a critical value of the 1d gas parameter. The accuracy and implications of our results are discussed in detail.

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G. E. Astrakharchik, D. Blume, S. Giorgini, B. E. Granger. 2003-10-31. Quantum Monte Carlo study of quasi-one-dimensional Bose gases. https://doi.org/10.1088/0953-4075%2F37%2F7%2F066

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