Article
Materials Science, Multidisciplinary
A. V. Syromyatnikov
Summary: In this study, a spin-1/2 Heisenberg antiferromagnet on the triangular lattice was discussed using the bond-operator technique (BOT). It was found that high-energy collective excitations and another high-energy quasiparticle exist in the system. Quantum fluctuations considerably alter the properties of conventional magnons, and the anomalous spin dynamics observed experimentally recently cannot be described by SWT.
Article
Physics, Multidisciplinary
Yuting Tan, Dao-Xin Yao
Summary: We investigate the effects of long-range interactions on the spin wave spectra and competition between magnetic phases on a frustrated square lattice. Analytical expressions for spin wave spectra are obtained for systems with competing Neel and (pi, o) stripe states, under any-order long-range interactions. Surprisingly, staggered long-range interaction suppresses quantum fluctuation and enlarges the ordered moment, extending the phase boundary between Neel and stripe states.
FRONTIERS OF PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Ana-Marija Nedic, Victor L. Quito, Yuriy Sizyuk, Peter P. Orth
Summary: We propose stacked two-dimensional lattice designs of frustrated and SO(3)-symmetric spin models that realize emergent Z3 Potts nematic order. Using Monte Carlo simulations and analytical calculations, we investigate the classical AFM-FM windmill model and map out its phase diagrams. We discover a state with composite Potts nematic order and relate it to Potts phases in other spin models.
Article
Materials Science, Multidisciplinary
Yuan Gao, Yu-Chen Fan, Han Li, Fan Yang, Xu-Tao Zeng, Xian-Lei Sheng, Ruidan Zhong, Yang Qi, Yuan Wan, Wei Li
Summary: The recently synthesized NBCP compound is found to be an ideal realization of a S = 1/2 triangular-lattice antiferromagnet with significant easy-axis spin exchange anisotropy. By combining automatic parameter searching and tensor-network simulations, a microscopic model is established to accurately describe the material's properties, fitting well with experimental data.
NPJ QUANTUM MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Tomonari Mizoguchi, Yoshihito Kuno, Yasuhiro Hatsugai
Summary: The study reveals characteristic band structures of fermions on a square kagome lattice, including flat bands and two spin-1 Dirac cones. Additionally, in the presence of an external field, the profile of the Chern numbers around the modified spin-1 Dirac cones coincides with the conventional one.
Article
Materials Science, Multidisciplinary
Zhen Zhao, Claudio Verdozzi, Ferdi Aryasetiawan
Summary: The self-consistent Green's function method is used to study the ground state spin patterns and magnetic structure factors of two-dimensional magnetic systems with frustrated spin-1/2 Heisenberg exchange coupling. The method shows improved accuracy compared to random phase approximation treatments in the case of scalar product interactions, while higher corrections are needed for cross-product interactions. The results indicate the potential advantages of this method in describing systems with a large number of atoms and long-range interactions.
Article
Physics, Multidisciplinary
Leonardo Martinelli, Davide Betto, Kurt Kummer, Riccardo Arpaia, Lucio Braicovich, Daniele Di Castro, Nicholas B. Brookes, Marco Moretti Sala, Giacomo Ghiringhelli
Summary: Resonant inelastic x-ray scattering (RIXS) was used to investigate the magnetic dynamics of infinite-layer cuprate CaCuO2. It was found that the single magnon decays into a broad continuum of excitations, with the spin-flip character dominating. This continuum is proposed to originate from the decay of the magnon into spinon pairs, related to the high ring exchange J(c) of CaCuO2.
Article
Materials Science, Multidisciplinary
M. Mohylna, J. Busa, M. Zukovic
Summary: This study investigates the formation and evolution of the SkX phase in a frustrated antiferromagnetic model on a triangular lattice with DMI, finding that even relatively small DMI intensity can lead to the appearance of the SkX phase. By using the parallel tempering Monte Carlo algorithm, the efficiency of locating phase boundaries between different phases separated by large or barely detectable energy barriers is demonstrated, which is particularly useful for strong first-order transitions.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2021)
Article
Physics, Multidisciplinary
Xin-Yang Liu, Yuan Gao, Han Li, Wentao Jin, Junsen Xiang, Hai Jin, Ziyu Chen, Wei Li, Gang Su
Summary: Quantum spin liquids have no magnetic order and can be cooled using magnetocaloric effects, making them promising for helium-free refrigeration in space applications and quantum technologies.
COMMUNICATIONS PHYSICS
(2022)
Article
Physics, Multidisciplinary
Tessa Cookmeyer, Johannes Motruk, Joel E. Moore
Summary: This study shows that under certain physical parameters, the additional four-spin interactions naturally generated in the Hubbard model will stabilize a chiral spin liquid of Kalmeyer-Laughlin type. By rewriting the interactions mean-field, a physical understanding of the origin of this spin liquid can be obtained.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Johannes Richter, Oleg Derzhko, Juergen Schnack
Summary: Over the last decade, the interest in the spin-1/2 Heisenberg antiferromagnet (HAF) on the square kagome lattice has been growing. This model system is a prominent example of quantum magnetism with a quantum paramagnetic ground state, flat-band physics near the saturation field, and quantum scars. Recent numerical investigations have revealed a gapless spin liquid in the square kagome magnet. The study also provides insights into specific heat, entropy, and susceptibility, revealing low-temperature shoulder below the major maximum and a change in curvature just at a specific temperature, attributed to low-lying singlet excitations and the singlet-triplet gap.
Article
Materials Science, Multidisciplinary
A. Syromyatnikov
Summary: We discuss the spin -21 J1-J2 model on the triangular lattice using bond-operator theory (BOT). We obtain four phases upon J2 increasing: the phase with 120 degrees ordering, the spin-liquid phase, the state with the collinear stripe order, and the spiral phase. The 120 degrees and the stripe phases are discussed in detail. All calculated static characteristics are in good agreement with previous numerical findings. We observe the evolution of the quasiparticles' spectra and dynamical structure factors (DSFs) in the 120 degrees phase. In the stripe phase, we observe the splitting of the magnon spectrum by quantum fluctuations, and the appearance of additional spin-1 and spin-0 quasiparticles that give anomalies in the DSFs. We also find a special spin-0 quasiparticle named the singlon that only produces a peak in the four-spin correlator and is invisible in the DSF.
Article
Materials Science, Multidisciplinary
Luc Testa, Peter Babkevich, Yasuyuki Kato, Kenta Kimura, Virgile Favre, Jose A. Rodriguez-Rivera, Jacques Ollivier, Stephane Raymond, Tsuyoshi Kimura, Yukitoshi Motome, Bruce Normand, Henrik M. Ronnow
Summary: We report high-resolution single-crystal inelastic neutron scattering measurements on the spin-1/2 antiferromagnet Ba(TiO)Cu-4(PO4)(4). The measurements reveal a complex mode structure with multiple characteristic features, allowing us to model the relevant magnetic interactions. Our findings demonstrate the importance of the intraplaquette DM interaction in enforcing robust magnetic order and opening a large gap at the Brillouin-zone center.
Article
Chemistry, Physical
Athanasios Papastathopoulos-Katsaros, Thomas M. Henderson, Gustavo E. Scuseria
Summary: We introduce S(z) spin-projection based on cluster mean-field theory and apply it to strongly correlated spin systems. By removing the restriction of S-z symmetry adaptation, we propose a generalized cluster mean-field theory that allows each cluster to access all S-z sectors. A projection scheme is used to restore global S-z, resulting in the Sz spin-projected generalized cluster mean-field method. These methods provide a qualitative and semi-quantitative description of Heisenberg lattices, suggesting their usefulness for studying inter-cluster correlations.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Rajiv R. P. Singh
Summary: We discuss the thermodynamic and magnetic properties of a competing high-spin/low-spin two-orbital two-electron model on a square lattice that may be relevant to nickelates like Ba2NiO2(AgSe)2. We focus on parameter regimes where a high-spin (S = 1) and a low-spin (S = 0) state are energetically close and discuss various exchange processes in such a system. The model we study is different from the recently proposed Kondo-necklace model, although there are similarities in terms of ground-state phases and symmetries. The properties of different phases and phase transitions can be easily distinguished experimentally.
