Emergent Potts Order in a Coupled Hexatic-Nematic XY model

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2022-OrthPeter-EmergentPotts.pdf (3.34 MB)

Date

2022-03-07

Authors

Drouin-Touchette, Victor
Orth, Peter
Coleman, Piers
Chandra, Premala
Lubensky, Tom C.

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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Authors

Orth, Peter

Person

Organizational Units

Physics and Astronomy

Organizational Unit

Ames Laboratory

Organizational Unit

Department

Physics and AstronomyAmes Laboratory

Abstract

Many two-dimensional physical systems ranging from atomic-molecular condensates to lowdimensional superconductors and liquid-crystal films are described by coupled XY models. The interplay of topology and competing interactions in these XY systems drives new kinds of emergent behavior relevant in both quantum and classical settings. Such coupled U(1) systems further introduce rich physics, bringing topology into contact with fractionalization and deconfinement. Motivated by a hidden-order phase transition in isotropic liquid-crystal 54COOBC films, we study the finite-temperature phase diagram of a minimalist hexatic-nematic XY model. We identify a small region of composite Potts order above the vortex-binding transition; this phase is characterized by relative hexatic-nematic ordering though both variables are disordered. We propose that the Potts order results from a confinement of fractional vortices into extended nematic defects and discuss the broader implications of fractional vortices and composite ordering in the wider class of coupled XY condensates.

Comments

This article is published as Drouin-Touchette, Victor, Peter P. Orth, Piers Coleman, Premala Chandra, and Tom C. Lubensky. "Emergent Potts Order in a Coupled Hexatic-Nematic XY model." Physical Review X 12, no. 1 (2022): 011043. DOI: 10.1103/PhysRevX.12.011043. Copyright 2022 American Physical Society. Attribution 4.0 International (CC BY 4.0) Posted with permission. DOE Contract Number(s): SC0020353; FG02-99ER45790; AC02-07CH11358.