Quantum Monte Carlo study of dynamics : from weakly interacting Bose gas to helium-like Bose fluid
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Data di Pubblicazione:
2013
Citazione:
Quantum Monte Carlo study of dynamics : from weakly interacting Bose gas to helium-like Bose fluid / F. Tramonto, R. Rota, D.E. Galli, S. Giorgini. ((Intervento presentato al 1. convegno Workshop : Condensed matter highlights
by the structure of matter research group tenutosi a Milano nel 2013.
Abstract:
We have studied dynamic properties of a system of hard-sphere bosons at zero temperature
through ab-initio estimations of the dynamic structure factor, S(q,w), from the dilute regime
up to a strongly interacting regime, paroganable to overpressurized liquid helium.
To this extent, we have used the Genetic Inversion via Falsification of Theories (GIFT) algorithm [1],
which perform accurate analytic continuations of imaginary time correlation functions under ill-posed
conditions. The imaginary time correlation functions have been computed with an exact numerical
method, the path integral ground state (PIGS) method [2]. With increasing density, we observe a
crossover of the dispersion of elementary excitations from a Bogoliubov-like spectrum to a
phonon-maxon-roton curve, characteristic of superfluid helium, and the emergence of a broad
multiphonon contribution accompanying the quasi-particle peak.
References:
[1] E. Vitali, M. Rossi, L. Reatto and D.E. Galli, Phys. Rev. B 82, 174510,(2010).
[2] A. Sarsa, K. E. Schmidt, and W. R. Magro, J. Chem. Phys. 113, 1366 (2000).
Tipologia IRIS:
14 - Intervento a convegno non pubblicato
Elenco autori:
F. Tramonto, R. Rota, D.E. Galli, S. Giorgini
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