Phase diagram, confining strings, and a new universality class in nematopolar matter

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Vafa, Farzan, Doostmohammadi, Amin
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866913642483548160
author Vafa, Farzan
Doostmohammadi, Amin
author_facet Vafa, Farzan
Doostmohammadi, Amin
contents We study a minimal model of a system with coexisting nematic and polar orientational orders, where one field tends to order and the other prefers isotropy. For strong coupling, the ordered field aligns the isotropic one, locking their orientations. The phase diagram reveals three distinct phases--nematopolar (aligned orders), nematic (independent orders), and isotropic (vanishing orders)--separated by continuous and discontinuous transitions, including a triple and a tricritical point. We find unique critical scaling for the nematopolar-nematic transition, distinct from standard nematic or polar universality classes. Additionally, in the locked nematopolar phase, we show nematic $+1/2$ topological defect pairs are connected and confined by strings with constant tension. These strings arise from frustration in locking the orientational orders and can be interpreted as elongated cores of $+1$ polar topological defects. When a sufficiently strong background field couples to the polar order, all topological defects are expelled from the region. Analytical predictions are quantitatively confirmed by numerical simulations.
format Preprint
id arxiv_https___arxiv_org_abs_2501_04769
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Phase diagram, confining strings, and a new universality class in nematopolar matter
Vafa, Farzan
Doostmohammadi, Amin
Soft Condensed Matter
Statistical Mechanics
We study a minimal model of a system with coexisting nematic and polar orientational orders, where one field tends to order and the other prefers isotropy. For strong coupling, the ordered field aligns the isotropic one, locking their orientations. The phase diagram reveals three distinct phases--nematopolar (aligned orders), nematic (independent orders), and isotropic (vanishing orders)--separated by continuous and discontinuous transitions, including a triple and a tricritical point. We find unique critical scaling for the nematopolar-nematic transition, distinct from standard nematic or polar universality classes. Additionally, in the locked nematopolar phase, we show nematic $+1/2$ topological defect pairs are connected and confined by strings with constant tension. These strings arise from frustration in locking the orientational orders and can be interpreted as elongated cores of $+1$ polar topological defects. When a sufficiently strong background field couples to the polar order, all topological defects are expelled from the region. Analytical predictions are quantitatively confirmed by numerical simulations.
title Phase diagram, confining strings, and a new universality class in nematopolar matter
topic Soft Condensed Matter
Statistical Mechanics
url https://arxiv.org/abs/2501.04769