Data di Pubblicazione:
2012
Citazione:
A non-perturbative approach to freezing of superfuid
4He in density functional theory / T. Minoguchi, D.E. Galli, M. Rossi, A. Yoshimori. - In: JOURNAL OF PHYSICS. CONFERENCE SERIES. - ISSN 1742-6588. - 400:Part.1(2012), pp. 012050.1-012050.4. [10.1088/1742-6596/400/1/012050]
Abstract:
Freezing of various classical liquids is successfully described by density functional
theory (DFT). On the other hand, so far no report has been published that DFT describes the
freezing of superfuid 4He correctly. In fact, DFT gives too stable solid phase and the superfuid
phase does not exist at finite positive pressures within a second order perturbation. In this paper
we try a non-perturbative version of DFT, that is modified weighted density approximation
(MWDA) to go beyond second order perturbation for the freezing of superfuid 4He. Via an
exact zero temperature quantum Monte-Carlo (QMC) method we have computed the equation
of state and the compressibility of superfuid 4He. By utilizing a recently introduced analytic
continuation method (the GIFT method), we have obtained also density response functions at
different densities from QMC imaginary time correlation functions. Contrary to second order
perturbation, by employing these QMC data as DFT input we find a too stable superfuid phase,
preventing freezing around the experimentally observed freezing pressure. We find the same
pathological behavior by using another model energy functional of superfuid 4He (Orsay-Trento
model). We conclude that the straightforward MWDA calculation gives such a poor result when
liquid-gas transition is present.
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
T. Minoguchi, D.E. Galli, M. Rossi, A. Yoshimori
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