Phase transitions in the spin-1/2 Heisenberg antiferromagnet on the dimerized diamond lattice

Fuente: arXiv
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Main Authors: Bärwolf, Ronja, Sushchyev, Alexander, Toldin, Francesco Parisen, Wessel, Stefan
Format: Preprint
Published: 2024
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author Bärwolf, Ronja
Sushchyev, Alexander
Toldin, Francesco Parisen
Wessel, Stefan
author_facet Bärwolf, Ronja
Sushchyev, Alexander
Toldin, Francesco Parisen
Wessel, Stefan
contents Using a combination of unbiased quantum Monte Carlo simulations and a decoupled dimer mean-field theory, we investigate the thermal and quantum phase transitions of the spin-1/2 Heisenberg model on the dimerized diamond lattice. We find that at sufficiently strong dimerization the system exhibits a quantum disordered ground state, in contrast to the antiferromagnetic phase stabilized at weak dimerization. We determine the quantum critical point and examine the thermodynamic responses in both regimes. The ratio for the critical interdimer ($J_c$) to intradimer ($J_D$) coupling is obtained as $J_c/J_D = 0.3615(5)$. Our results show that the decoupled dimer mean-field theory well captures the competition between the local singlet formation and the antiferromagnetic ordering tendency, and thus provides an appropriate qualitative description of this three-dimensional quantum magnet, in contrast to the conventional mean-field decoupling. We also examine the differences in the ordering temperatures between the antiferromagnetic and the ferromagnetic spin-1/2 Heisenberg model on the diamond lattice based on quantum Monte Carlo simulations.
format Preprint
id arxiv_https___arxiv_org_abs_2410_13706
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Phase transitions in the spin-1/2 Heisenberg antiferromagnet on the dimerized diamond lattice
Bärwolf, Ronja
Sushchyev, Alexander
Toldin, Francesco Parisen
Wessel, Stefan
Strongly Correlated Electrons
Using a combination of unbiased quantum Monte Carlo simulations and a decoupled dimer mean-field theory, we investigate the thermal and quantum phase transitions of the spin-1/2 Heisenberg model on the dimerized diamond lattice. We find that at sufficiently strong dimerization the system exhibits a quantum disordered ground state, in contrast to the antiferromagnetic phase stabilized at weak dimerization. We determine the quantum critical point and examine the thermodynamic responses in both regimes. The ratio for the critical interdimer ($J_c$) to intradimer ($J_D$) coupling is obtained as $J_c/J_D = 0.3615(5)$. Our results show that the decoupled dimer mean-field theory well captures the competition between the local singlet formation and the antiferromagnetic ordering tendency, and thus provides an appropriate qualitative description of this three-dimensional quantum magnet, in contrast to the conventional mean-field decoupling. We also examine the differences in the ordering temperatures between the antiferromagnetic and the ferromagnetic spin-1/2 Heisenberg model on the diamond lattice based on quantum Monte Carlo simulations.
title Phase transitions in the spin-1/2 Heisenberg antiferromagnet on the dimerized diamond lattice
topic Strongly Correlated Electrons
url https://arxiv.org/abs/2410.13706