Phase transitions in the spin- 12 Heisenberg antiferromagnet on the dimerized diamond lattice

Physical review. B./Physical review. B, Journal Year: 2025, Volume and Issue: 111(8)

Published: Feb. 19, 2025

Using a combination of unbiased quantum Monte Carlo simulations and decoupled dimer mean-field theory, we investigate the thermal phase transitions spin-12 Heisenberg model on dimerized diamond lattice. We find that at sufficiently strong dimerization system exhibits disordered ground state, in contrast to antiferromagnetic stabilized weak dimerization. determine critical point examine thermodynamic responses both regimes. The ratio for interdimer (Jc) intradimer (JD) coupling is obtained as Jc/JD=0.3615(5). Our results show theory well captures competition between local singlet formation ordering tendency, thus provides an appropriate qualitative description this three-dimensional magnet, conventional decoupling. also differences temperatures ferromagnetic spin-12 lattice based simulations. Published by American Physical Society 2025

Language: Английский

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Spin dynamics of an easy-plane Dirac spin liquid in a frustrated XY model: Application to honeycomb cobaltates

Physical review. B./Physical review. B, Journal Year: 2025, Volume and Issue: 111(10)

Published: March 27, 2025

Language: Английский

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Phase diagram of the XXZ pyrochlore model from pseudo-Majorana functional renormalization group

Physical review. B./Physical review. B, Journal Year: 2025, Volume and Issue: 111(13)

Published: April 24, 2025

We calculate the magnetic phase diagram of spin-1/2 nearest neighbor XXZ pyrochlore model using pseudo-Majorana functional renormalization group in temperature flow formalism. Our as a function and coupling ratio, allowing both longitudinal transverse couplings to be ferromagnetic antiferromagnetic, reveals large nonmagnetic regime at low temperatures, which includes quantum spin ice near antiferromagnetic Ising model, well Heisenberg XY models. are able detect transitions via critical finite size scaling down temperatures two orders magnitude smaller than interactions, demonstrating remarkably good performance our method upon approaching ground state. Specifically, low-temperature transition from zero-flux into shows very agreement with previous Monte Carlo results. Comparing findings classical results, we identify order-by-disorder effect model. In magnetically disordered regimes, find characteristic patterns broadened pinch points structure factor investigate their evolution when ordered phases. also compute linear responses lattice symmetry breaking perturbations possible nematic state Published by American Physical Society 2025

Language: Английский

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Field-induced spin liquid in the decorated square-kagome antiferromagnet nabokoite $${{{\rm{KCu}}}}_{7}{{{\rm{TeO}}}}_{4}{({{{\rm{SO}}}}_{4})}_{5}{{\rm{Cl}}}$$

Communications Materials, Journal Year: 2025, Volume and Issue: 6(1)

Published: May 12, 2025

Language: Английский

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Pseudo-fermion functional renormalization group with magnetic fields

Physical review. B./Physical review. B, Journal Year: 2024, Volume and Issue: 109(17)

Published: May 7, 2024

The pseudo-fermion functional renormalization group is generalized to treat spin Hamiltonians with finite magnetic fields, enabling its application arbitrary lattice models linear and bilinear terms in the operators. We discuss detail an efficient numerical implementation of this approach making use system's symmetries. Particularly, we demonstrate that inclusion small symmetry-breaking seed fields regularizes divergences susceptibility at phase transitions. This allows investigation within magnetically ordered phases $T=0$ physical limit vanishing parameter $\mathrm{\ensuremath{\Lambda}}$. explore capabilities limitations method extension for Heisenberg on square, honeycomb, triangular lattices. While zero-field magnetizations these systems are systematically overestimated, types orders correctly captured, even if local orientations field chosen differently than realized order. Furthermore, magnetization curve square antiferromagnet shows good agreement error controlled methods. In future, group, which also possible three-dimensional systems, will enable a variety additional interesting applications such as plateaus.

Language: Английский

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High temperature series expansions of S = 1/2 Heisenberg spin models: Algorithm to include the magnetic field with optimized complexity

SciPost Physics, Journal Year: 2024, Volume and Issue: 17(4)

Published: Oct. 7, 2024

This work presents an algorithm for calculating high temperature series expansions (HTSE) of Heisenberg spin models with S=1/2 S=1/2 in the thermodynamic limit. accounts presence a magnetic field. The paper begins comprehensive introduction to HTSE and then focuses on identifying bottlenecks that limit computation higher order coefficients. calculations involve two key steps: graph enumeration lattice trace each graph. non-zero field adds complexity expansion because previously irrelevant graphs must now be considered: bridged graphs. We present efficient method deduce contribution these from sub-graphs, drastically reduces time calculation last coefficient (in practice increasing by one at almost no cost). Previous articles authors have utilized based this algorithm, but without providing detailed explanations. complete is publicly available, as well many various interactions.

Language: Английский

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Magnetism in the two-dimensional dipolar XY model

arXiv (Cornell University), Journal Year: 2023, Volume and Issue: unknown

Published: Jan. 1, 2023

Motivated by a recent experiment on square-lattice Rydberg atom array realizing long-range dipolar XY model [Chen et al., Nature (2023)], we numerically study the model's equilibrium properties. We obtain phase diagram, critical properties, entropies, variance of magnetization, and site-resolved correlation functions. consider both ferromagnetic antiferromagnetic interactions apply quantum Monte Carlo pseudo-Majorana functional renormalization group techniques, generalizing latter to U(1) symmetric setting. Our simulations perform extensive thermometry for first time in arrays establish conditions adiabaticity thermodynamic equilibrium. On side experiment, determine entropy per particle S/N~0.5, close one at temperature, S_c/N = 0.585(15). The suggest presence an out-of-equilibrium plateau large distances function, thus motivating future studies non-equilibrium dynamics system.

Language: Английский

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A pseudofermion functional renormalization group study of dipolar-octupolar pyrochlore magnets

arXiv (Cornell University), Journal Year: 2023, Volume and Issue: unknown

Published: Jan. 1, 2023

Motivated by recent experiments on Ce$_2$Zr$_2$O$_7$ that reveal a dynamic, liquid-like ground state, we study the nearest neighbor XYZ Hamiltonian of dipolar-octupolar pyrochlore magnets with pseudofermion functional renormalization group (PFFRG), which is numerically implemented SpinParser software. Taking interaction between octupolar components to be dominant and antiferromagnetic, map out phase diagram demarcating quantum disordered magnetically ordered states. We identify four distinct phases, namely $0$-flux $π$-flux spin ices, all-in-all-out magnetic orders along local $z$ $x$ axes. further use static two-spin correlations output PFFRG algorithm compute polarized neutron scattering cross-sections, are able capture several qualitative features observed experimentally, in materially relevant parameter regime stabilizes ice. Our results provide support for liquid state Ce$_2$Zr$_2$O$_7$.

Language: Английский

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Candidate quantum disordered intermediate phase in the Heisenberg antiferromagnet on the maple-leaf lattice

arXiv (Cornell University), Journal Year: 2023, Volume and Issue: unknown

Published: Jan. 1, 2023

Quantum antiferromagnets on geometrically frustrated lattices have long attracted interest for the formation of quantum disordered states and possible emergence spin liquid (QSL) ground states. Here we turn to nearest-neighbor spin-$1/2$ Heisenberg antiferromagnet maple-leaf lattice, which is known relieve frustration by canted $120^{\circ}$ magnetic order or valence bond crystal when varying anisotropy. Employing a pseudo-fermion functional renormalization group approach assess its state phase diagram in detail, present evidence QSL regime sandwiched between these two limiting phases. The such might signal proximity deconfined critical point from it emerges, that potentially accessible tuning exchange couplings. Our conclusions are based large-scale simulations involving careful finite-size scaling analysis behavior susceptibility spin-spin correlation functions under flow.

Language: Английский

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Pseudo-fermion functional renormalization group with magnetic fields

arXiv (Cornell University), Journal Year: 2023, Volume and Issue: unknown

Published: Jan. 1, 2023

The pseudo-fermion functional renormalization group is generalized to treat spin Hamiltonians with finite magnetic fields, enabling its application arbitrary lattice models linear and bilinear terms in the operators. We discuss detail an efficient numerical implementation of this approach making use system's symmetries. Particularly, we demonstrate that inclusion small symmetry breaking seed fields regularizes divergences susceptibility at phase transitions. This allows investigation within magnetically ordered phases $T=0$ physical limit vanishing parameter $\Lambda$. explore capabilities limitations method extension for Heisenberg on square, honeycomb triangular lattices. While zero-field magnetizations these systems are systematically overestimated, types orders correctly captured, even if local orientations field chosen differently than realized order. Furthermore, magnetization curve square antiferromagnet shows good agreement error controlled methods. In future, group, which also possible three dimensional systems, will enable a variety additional interesting applications such as plateaus.

Language: Английский

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