Constructing Emergent U(1) Symmetries in the Gamma-prime $\left(\bf Γ^{\prime} \right)$ model

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Ramchandani, Sagar, Trebst, Simon, Hickey, Ciarán
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908497767038976
author Ramchandani, Sagar
Trebst, Simon
Hickey, Ciarán
author_facet Ramchandani, Sagar
Trebst, Simon
Hickey, Ciarán
contents Frustrated magnets can elude the paradigm of conventional symmetry breaking and instead exhibit signatures of emergent symmetries at low temperatures. Such symmetries arise from "accidental" degeneracies within the ground state manifold and have been explored in a number of disparate models, in both two and three dimensions. Here we report the systematic construction of a family of classical spin models that, for a wide variety of lattice geometries with triangular motifs in one, two and three spatial dimensions, such as the kagome or hyperkagome lattices, exhibit an emergent, continuous U(1) symmetry. This is particularly surprising because the underlying Hamiltonian actually has very little symmetry - a bond-directional, off-diagonal exchange model inspired by the microscopics of spin-orbit entangled materials (the $Γ^{\prime}$-model). The construction thus allows for a systematic study of the interplay between the emergent continuous U(1) symmetry and the underlying discrete Hamiltonian symmetries in different lattices across different spatial dimensions. We discuss the impact of thermal and quantum fluctuations in lifting the accidental ground state degeneracy via the thermal and quantum order-by-disorder mechanisms, and how spatial dimensionality and lattice symmetries play a crucial role in shaping the physics of the model. Complementary Monte Carlo simulations, for representative one-, two-, and three-dimensional lattice geometries, provide a complete account of the thermodynamics and confirm our analytical expectations.
format Preprint
id arxiv_https___arxiv_org_abs_2411_02070
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Constructing Emergent U(1) Symmetries in the Gamma-prime $\left(\bf Γ^{\prime} \right)$ model
Ramchandani, Sagar
Trebst, Simon
Hickey, Ciarán
Strongly Correlated Electrons
Frustrated magnets can elude the paradigm of conventional symmetry breaking and instead exhibit signatures of emergent symmetries at low temperatures. Such symmetries arise from "accidental" degeneracies within the ground state manifold and have been explored in a number of disparate models, in both two and three dimensions. Here we report the systematic construction of a family of classical spin models that, for a wide variety of lattice geometries with triangular motifs in one, two and three spatial dimensions, such as the kagome or hyperkagome lattices, exhibit an emergent, continuous U(1) symmetry. This is particularly surprising because the underlying Hamiltonian actually has very little symmetry - a bond-directional, off-diagonal exchange model inspired by the microscopics of spin-orbit entangled materials (the $Γ^{\prime}$-model). The construction thus allows for a systematic study of the interplay between the emergent continuous U(1) symmetry and the underlying discrete Hamiltonian symmetries in different lattices across different spatial dimensions. We discuss the impact of thermal and quantum fluctuations in lifting the accidental ground state degeneracy via the thermal and quantum order-by-disorder mechanisms, and how spatial dimensionality and lattice symmetries play a crucial role in shaping the physics of the model. Complementary Monte Carlo simulations, for representative one-, two-, and three-dimensional lattice geometries, provide a complete account of the thermodynamics and confirm our analytical expectations.
title Constructing Emergent U(1) Symmetries in the Gamma-prime $\left(\bf Γ^{\prime} \right)$ model
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2411.02070