Low-Lying Magnetic Excitation of the Shastry-Sutherland Model
arXiv:cond-mat/0101125 · doi:10.1103/PhysRevLett.86.520
Abstract
By using perturbation calculation and numerical diagonalization, low-energy spin dynamics of the Shastry-Sutherland model is investigated paying particular attention to the two-particle coherent motion. In addition to spin-singlet- and triplet bound states, we find novel branches of coherent motion of a bound quintet pair, which are usually unstable because of repulsion. Unusual dispersion observed in neutron-scattering measurements are explained by the present theory. The importance of the effects of phonon is also pointed out.
4 pages, 6 figures combined into 1 PSfile. Final version to appear in Phys.Rev.Lett. (Jan. 2000)