Ground state properties of the Heisenberg-compass model on the square lattice

Fuente: arXiv
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Autori principali: Khatua, Subhankar, Howson, Griffin C., Gingras, Michel J. P., Rau, Jeffrey G.
Natura: Preprint
Pubblicazione: 2024
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author Khatua, Subhankar
Howson, Griffin C.
Gingras, Michel J. P.
Rau, Jeffrey G.
author_facet Khatua, Subhankar
Howson, Griffin C.
Gingras, Michel J. P.
Rau, Jeffrey G.
contents Compass models provide insights into the properties of Mott-insulating materials that host bond-dependent anisotropic interactions between their pseudospin degrees of freedom. In this article, we explore the classical and quantum ground state properties of one such model relevant to certain layered perovskite materials akin to Ba$_2$IrO$_4$ - namely, the Heisenberg-compass model on the square lattice. We first investigate the ground state phase diagram of this model using classical Monte Carlo simulations. These reveal that the low temperature classical phase diagram is divided into six different classes of long-range ordered phases, including four phases that exhibit an order by disorder selection and two phases that are stabilized energetically. This model admits a special duality transformation, known as the Klein duality, conveniently allowing to map one region of coupling parameters onto another and constraining the phase diagram, and which we exploit in our study. From the analysis of the zero-point energy and the free energy of the spin waves, we find that order by quantum disorder at zero temperature and order by thermal disorder select the same orderings as those found from classical Monte Carlo simulations. We further investigate the quantum ground states of this model using numerical exact diagonalization on small clusters by exploiting the translational symmetry of the square lattice. We obtain a ground state phase diagram bearing close resemblance to that found from the classical analysis.
format Preprint
id arxiv_https___arxiv_org_abs_2404_02196
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Ground state properties of the Heisenberg-compass model on the square lattice
Khatua, Subhankar
Howson, Griffin C.
Gingras, Michel J. P.
Rau, Jeffrey G.
Strongly Correlated Electrons
Statistical Mechanics
Compass models provide insights into the properties of Mott-insulating materials that host bond-dependent anisotropic interactions between their pseudospin degrees of freedom. In this article, we explore the classical and quantum ground state properties of one such model relevant to certain layered perovskite materials akin to Ba$_2$IrO$_4$ - namely, the Heisenberg-compass model on the square lattice. We first investigate the ground state phase diagram of this model using classical Monte Carlo simulations. These reveal that the low temperature classical phase diagram is divided into six different classes of long-range ordered phases, including four phases that exhibit an order by disorder selection and two phases that are stabilized energetically. This model admits a special duality transformation, known as the Klein duality, conveniently allowing to map one region of coupling parameters onto another and constraining the phase diagram, and which we exploit in our study. From the analysis of the zero-point energy and the free energy of the spin waves, we find that order by quantum disorder at zero temperature and order by thermal disorder select the same orderings as those found from classical Monte Carlo simulations. We further investigate the quantum ground states of this model using numerical exact diagonalization on small clusters by exploiting the translational symmetry of the square lattice. We obtain a ground state phase diagram bearing close resemblance to that found from the classical analysis.
title Ground state properties of the Heisenberg-compass model on the square lattice
topic Strongly Correlated Electrons
Statistical Mechanics
url https://arxiv.org/abs/2404.02196