We compute several ground-state properties and the dynamical structure factor of a zero-temperature system of Bosons interacting with the 2D screened Coulomb (2D-SC) potential. We resort to the exact shadow path integral ground state (SPIGS) quantum Monte Carlo method to compute the imaginary-time correlation function of the model, and to the genetic algorithm via falsification of theories (GIFT) to retrieve the dynamical structure factor. We provide a detailed comparison of ground-state properties and collective excitations of 2D-SC and 4He atoms. The roton energy of the 2D-SC system is an increasing function of density, and not a decreasing one as in 4He. This result is in contrast with the view that the roton is the soft mode of the fluid–solid transition. We uncover a remarkable quasi-universality of backflow and of other properties when expressed in terms of the amount of short-range order as quantified by the height of the first peak of the static structure factor.
Roton Excitations and the Fluid–Solid Phase Transition in Superfluid 2D Yukawa Bosons / S. Molinelli, D.E. Galli, L. Reatto, M. Motta. - In: JOURNAL OF LOW TEMPERATURE PHYSICS. - ISSN 0022-2291. - 185:1-2(2016), pp. 39-58.
|Titolo:||Roton Excitations and the Fluid–Solid Phase Transition in Superfluid 2D Yukawa Bosons|
GALLI, DAVIDE EMILIO (Corresponding)
REATTO, LUCIANO (Penultimo)
|Parole Chiave:||Dynamical properties; Quantum liquids; Soft-core interaction; Atomic and Molecular Physics, and Optics; Materials Science (all); Condensed Matter Physics|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Data di pubblicazione:||2016|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1007/s10909-016-1628-3|
|Appare nelle tipologie:||01 - Articolo su periodico|