Excitation spectrum of the two-dimensional quantum antiferromagnetic Heisenberg model: Wigner-Jordan fermions or spin waves

Publisher Website
Google Scholar
Abstract
The excitation spectrum of the quantum antiferromagnetic Heisenberg model for a square lattice, as predicted from the in-phase flux state of Wigner-Jordan fermions, is calculated and compared with that calculated from conventional spin-wave theory. While the two spectra are overall similar, there are significant differences for short-wavelength excitations. The ratio of the excitation energy at wave vector (π/2,π/2) to that at (π/2,0) is predicted to be √2 for the Wigner-Jordan fermion excitations, and 2/ √3 for the spin-wave excitations. At long wavelengths, in contrast to the gapped spin-wave spectrum of Auerbach and Arovas, the excitation spectrum of Wigner-Jordan fermions is gapless at any finite temperature. Possible experimental examination of the excitation spectrum is discussed.