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arXiv · 1109.6133

Condensate fraction in liquid 4He at zero temperature

Riccardo Rota·Jordi Boronat
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Abstract

We present results of the one-body density matrix (OBDM) and the condensate fraction n_0 of liquid 4He calculated at zero temperature by means of the Path Integral Ground State Monte Carlo method. This technique allows to generate a highly accurate approximation for the ground state wave function Psi_0 in a totally model-independent way, that depends only on the Hamiltonian of the system and on the symmetry properties of Psi_0. With this unbiased estimation of the OBDM, we obtain precise results for the condensate fraction n_0 and the kinetic energy K of the system. The dependence of n_0 with the pressure shows an excellent agreement of our results with recent experimental measurements. Above the melting pressure, overpressurized liquid 4He shows a small condensate fraction that has dropped to 0.8% at the highest pressure of p = 87 bar.

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Riccardo Rota, Jordi Boronat. 2011-09-28. Condensate fraction in liquid 4He at zero temperature. https://doi.org/10.1007/s10909-011-0410-9

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