2015/04/30 by M. Powalski, G. S. Uhrig, K. P. Schmidt · 2 citations
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.115.207202
published as Phys. Rev. Lett. 115, 207202 (2015) · 10 pages, 3 figures
arxiv created 2015/11/12 · arxiv updated 2015/11/13
A quantitative description of magnons in long-range ordered quantum antiferromagnets is presented which is consistent from low to high energies. It is illustrated for the generic S=1/2 Heisenberg model on the square lattice. The approach is based on a continuous similarity transformation in momentum space using the scaling dimension as truncation criterion. Evidence is found for significant magnon-magnon attraction inducing a Higgs resonance. The high-energy roton minimum in the magnon dispersion appears to be induced by strong magnon-Higgs scattering.