Excitation spectra and ground state properties of the layered spin-12frustrated antiferromagnetsCs2CuCl4andCs2CuBr4

2006/12/31 by J. O. Fjærestad, John O. Fjaerestad, Weihong Zheng +4 · 5 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Anisotropy #Antiferromagnetism #Condensed matter physics #Excitation #Excited state #Ferromagnetism #Ground state #Heisenberg model #Magnetization #Magnon #Organic and Molecular Conductors Research #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Spin wave #Wave vector #cond-mat.str-el

paper · pdf · doi:10.1103/physrevb.75.174447

10 pages, 8 figures

arxiv created 2006/12/31 · openalex publication_date 2007/05/31 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

We use series expansion methods to study ground- and excited-state properties in the helically ordered phase of spin-1∕2 frustrated antiferromagnets on an anisotropic triangular lattice. We calculate the ground state energy, ordering wave vector, sublattice magnetization and one-magnon excitation spectrum for parameters relevant to Cs₂CuCl₄ and Cs₂CuBr₄. Both materials are modeled in terms of a Heisenberg model with spatially anisotropic exchange constants; for Cs₂CuCl₄ we also take into account the additional Dzyaloshinskii-Moriya (DM) interaction. We compare our results for Cs₂CuCl₄ with unpolarized neutron scattering experiments and find good agreement. In particular, the large quantum renormalizations of the one-magnon dispersion are well accounted for in our analysis, and inclusion of the DM interaction brings the theoretical predictions for the ordering wave vector and the magnon dispersion closer to the experimental results.

Citations

• On the ground state properties of the anisotropic triangular antiferromagnet
• Finite-temperature dynamical magnetic susceptibility of quasi-one-dimensional frustrated spin-12Heisenberg antiferromagnets
• Spin-wave analysis to the spatially anisotropic Heisenberg antiferromagnet on a triangular lattice
• Spin Liquid State in an Organic Mott Insulator with a Triangular Lattice
• Theory of the algebraic vortex liquid in an anisotropic spin-12triangular antiferromagnet
• A thermodynamic theory of “weak” ferromagnetism of antiferromagnetics
• Direct Measurement of the Spin Hamiltonian and Observation of Condensation of Magnons in the 2D Frustrated Quantum MagnetCs2CuCl4
• Anisotropic Superexchange Interaction and Weak Ferromagnetism

Cited by

• Thermodynamics of the up-up-down phase of theS=12triangular-lattice antiferromagnetCs2CuBr4
• Torque equilibrium spin wave theory study of anisotropy and Dzyaloshinskii-Moriya interaction effects on the indirect K-edge RIXS spectrum of a triangular lattice antiferromagnet
• Hybridization and Decay of Magnetic Excitations in Two-Dimensional Triangular Lattice Antiferromagnets
• Interplay between spatial anisotropy and next-nearest-neighbor exchange interactions in the triangular Heisenberg model
• Spin-liquid phase in a spatially anisotropic frustrated antiferromagnet: A Schwinger boson mean-field approach