Multiple magnon modes in spin-1/2 Heisenberg antiferromagnet on simple square lattice in strong magnetic field

Abstract

We discuss spin-$\frac{1}{2}$ Heisenberg antiferromagnet on simple square lattice in magnetic field $H$ using recently proposed bond-operator technique. It is well known that magnetically ordered phases of quantum magnets are well described at least qualitatively by the conventional spin-wave theory that only introduces quantum corrections into the classical solution of the problem. We observe that quantum fluctuations change drastically dynamical properties of the considered model at $H$ close to its saturation value: the dynamical structure factor shows anomalies corresponding to Green's function poles which have no counterparts in the spin-wave theory. That is, quantum fluctuations produce multiple short-wavelength magnon modes not changing qualitatively the long-wavelength spin dynamics. Our results are in agreement with previous quantum Monte-Carlo simulations and exact diagonalization of finite clusters.

arXiv comment11 pages, 10 figures

References in corpus (19)

• Finite-Size Scaling of the Ground State Parameters of the Two-Dimensional Heisenberg Model
• Intense paramagnon excitations in a large family of high-temperature superconductors
• Spontaneous Magnon Decays
• Fractional excitations in the square-lattice quantum antiferromagnet
• Anomalous High-Energy Spin Excitations in La2CuO4
• Nearly deconfined spinon excitations in the square-lattice spin-1/2 Heisenberg antiferromagnet
• Flat spin wave dispersion in a triangular antiferromagnet
• Dynamical structure factor of the $J_1-J_2$ Heisenberg model on the triangular lattice: magnons, spinons, and gauge fields
• Instability of antiferromagnetic magnons in strong fields
• The antiferromagnetic spin-1/2 Heisenberg model on the square lattice in a magnetic field
• Roton minimum as fingerprint of magnon-Higgs scattering in ordered quantum antiferromagnets
• Spectrum of short-wavelength magnons in two-dimensional quantum Heisenberg antiferromagnet on a square lattice: third order expansion in 1/S
• High-Energy Continuum of Magnetic Excitations in the Two-Dimensional Quantum Antiferromagnet Sr2CuO2Cl2
• Numerical evidence for unstable magnons at high fields in the Heisenberg antiferromagnet on the square lattice
• Hybridization and Decay of Magnetic Excitations in two-dimensional Triangular Lattice Antiferromagnets
• Hydrodynamic relation in 2D Heisenberg antiferromagnet in a field
• Collective excitations in spin-1/2 magnets through bond-operator formalism designed both for paramagnetic and ordered phases
• Elementary excitations in the ordered phase of spin-1/2 J1-J2 model on square lattice
• Collective excitations in two-dimensional antiferromagnet in strong magnetic field

Cited by in corpus (5)

• Novel elementary excitations in spin-1/2 antiferromagnets on the triangular lattice
• Unusual dynamics of spin-1/2 antiferromagnets on the triangular lattice in magnetic field
• Dynamics of spin-1/2 $J_1$-$J_2$ model on the triangular lattice
• Spin dynamics in the square-lattice cupola system Ba(TiO)Cu${}_4$(PO${}_4$)${}_4$
• Elementary excitations in undoped layered cuprates