Scalar fields: from domain walls to nanotubes and fulerenes

Abstract

In this work we review some features of topological defects in field theory models for real scalar fields. We investigate topological defects in models involving one and two or more real scalar fields. In models involving a single field we examine two different subclasses of models, which support one or more topological defects. In models involving two or more real scalar fields, we explore the presence of defects that live inside topological defects, and junctions and networks of defects. In the case of junctions of defects we investigte structures that simulate nanotubes and fulerenes. Our investigations may also be used to describe nonlinear properties of polymers, Langmuir films and optical solitons in fibers.Comment: Revtex, 10 pages, 5 figures. Talk presented at XXII Encontro Nacional de Fisica de Particulas e Campos, Sao Lourenco, MG, Brazil, October 2001; v2, 2 references adde

New family of potentials with analytical twiston-like solutions

“…Such a shift costs finite energy whose value is exactly the same computed in [5,6]. We believe that the procedure presented in this letter can be applied to other interesting scenarios where the a two scalar fields model describes a molecular dynamics like polyaniline [16], leucoemeraldine [17] or fullerene [18]. There are other models describing crystalline polyethylene based on sine-Gordon potentials, as the one investigated in [19], which could be revisited with this method.…”

Self-gravitating kinks in two-dimensional pseudo-Riemannian universes

“…Along this paper we have been investigating the interplay between Jackiw-Teitelboim gravity and travelling kink solutions in severals scalar field theories. According to the classification given by Bazeia in [41], all these theories are of type I, models with a single scalar field supporting structureless kinks. In fact, they all belong to a subclass in which the energy density is symmetric around the center of the kink, a condition which does not apply for other models within type I such as the φ 6 kink [42].…”

Domain wall and periodic solutions of coupled asymmetric double well models

“…8 For structural phase transformations the solutions provide novel domain wall arrays, e.g., periodic antiphase boundaries and twin boundaries. 8 For structural phase transformations the solutions provide novel domain wall arrays, e.g., periodic antiphase boundaries and twin boundaries.…”

“…However, if a third order term becomes symmetry allowed, one need not go to the sixth order term for the transition to be of first order. 8 For triangular or hexagonal symmetry crystals two different order parameters ͑e.g., strain and shuffle͒ can couple with each other being described by an asymmetric double well. This situation occurs in body-centered cubic ͑bcc͒ to face-centered cubic ͑fcc͒ reconstructive structural phase transitions in crystals, the -phase transition in various elements and alloys, 2 isotropic to nematic phase transition in liquid crystals, 3 and in the hydrogen chains in hydrogen bonded materials.…”