Tunable rotons in square-lattice antiferromagnets under strong magnetic fields

2014/03/31 by Yurika Kubo, Susumu Kurihara · 1 citation
Physics and Astronomy · #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #Theoretical and Computational Physics #cond-mat.str-el

paper · pdf · doi:10.1103/physrevb.90.014421

published as Phys. Rev. B 90, 014421(2014) · 9 pages, 6 figures

openalex publication_date 2014/07/17 · arxiv created 2014/07/22 · arxiv updated 2014/07/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

Excitation spectra of square lattice Heisenberg antiferromagnets in magnetic fields are investigated by the spin-wave theory. It is pointed out that a rotonlike structure appears in a narrow range of magnetic fields as a result of strong nonlinear effects. It is shown that the energy gap and the mass of the ``roton'' are quite sensitive to the magnetic field: the roton gap softens rapidly and eventually closes as a precursor of a quantum phase transition. The possibility of the experimental observation of the roton and a new ground state after its softening are discussed.

Citations

• Hydrodynamic relation in a two-dimensional Heisenberg antiferromagnet in a field
• Numerical evidence for unstable magnons at high fields in the Heisenberg antiferromagnet on the square lattice
• Spin Waves and Electronic Interactions inLa2CuO4
• Instability of Antiferromagnetic Magnons in Strong Fields

Cited by

• 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