Condensate fraction in liquid 4He at zero temperature
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.
Keywords
Cite
@article{arxiv.1109.6133,
title = {Condensate fraction in liquid 4He at zero temperature},
author = {Riccardo Rota and Jordi Boronat},
journal= {arXiv preprint arXiv:1109.6133},
year = {2015}
}
Comments
12 pages. 4 figures. Accepted for publication on "Journal of Low Temperature Physics"