Geometrical and topological study of the Kosterlitz–Thouless phase transition in the XY model in two dimensions

Year: 2021

Authors: Bel-Hadj-Aissa G., Gori M., Franzosi R., Pettini M.

Autors Affiliation: Univ Siena, Dipartimento Sci Fis Terra & Ambiente DSFTA, Via Roma 56, I-53100 Siena, Italy; QSTAR, Largo Enrico Fermi 2, I-50125 Florence, Italy; CNR, Ist Nazl Ott, Largo Enrico Fermi 2, I-50125 Florence, Italy; Howard Univ, Quantum Biol Lab, 2400 6th St NW, Washington, DC 20059 USA; Aix Marseille Univ, F-13288 Marseille, France; CNRS Ctr Phys Theor UMR7332, F-13288 Marseille, France.

Abstract: Phase transitions do not necessarily correspond to a symmetry- breaking phenomenon. This is the case of the Kosterlitz–Thouless (KT) phase transition in a two-dimensional classical XY model, a typical example of a tran- sition stemming from a deeper phenomenon than a symmetry-breaking. Actually, the KT transition is a paradigmatic example of the successful application of topo- logical concepts to the study of phase transition phenomena in the absence of an order parameter. Topology conceptually enters through the meaning of defects in real space. In the present work, the same kind of KT phase transition in a two-dimensional classical XY model is tackled by resorting again to a topological viewpoint, however focussed on the energy level sets in phase space rather than on topological defects in real space. Also from this point of view, the origin of the KT transition can be attributed to a topological phenomenon. In fact, the tran- sition is detected through peculiar geometrical changes of the energy level sets which, after a theorem in differential topology, are direct probes of topological changes of these level sets.

Journal/Review: JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT

Volume: 2021 (2)      Pages from: 023206-1  to: 023206-33

More Information: This work has been done within the framework of the Master thesis work of Ghofrane Bel Hadj Aissa performed under the supervision of Matteo Gori and Marco Pettini within the framework of the project MOLINT which has received funding from the Excellence Initiative of Aix-Marseille University-A*Midex, a French ´Investissements d´Avenir´ Programme. Roberto Franzosi and Ghofrane Bel Hadj Aissa thank the support by the QuantERA, ERA-NET Co-fund 731473 (Project Q-CLOCKS), Italy. Matteo Gori thanks the financial support of DARPA (USA) for his long term visit at Howard University at Washington D.C.
KeyWords: classical phase transitions, dynamical processes, numerical simula- tions
DOI: 10.1088/1742-5468/abda27

Citations: 7
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-11-17
References taken from IsiWeb of Knowledge: (subscribers only)
Connecting to view paper tab on IsiWeb: Click here
Connecting to view citations from IsiWeb: Click here