2005/03/03 by Frank Krüger, Krüger, Frank, Stefan Scheidl +1
Physics and Astronomy · #FOS: Physical sciences #Other Condensed Matter (cond-mat.other) #cond-mat.other
paper · pdf · doi:10.48550/arxiv.cond-mat/0503076
4 pages, 3 figures, errors in references removed
arxiv created 2005/03/07 · arxiv updated 2009/12/01
We develop a novel renormalization approach for frustrated quantum antiferromagnets. It is designed to consistently treat spin-wave interactions all over the magnetic Brillouin zone, including high-energy modes in outer regions as well as low energy modes in the center. Focusing on the paradigmatic J1-J2 model, we find a unifying description of the second-order transition between the Néel phase and the paramagnetic phase and the first-order transition between the Néel phase and the columnar phase. Our approach provides explicit results for the renormalized values of the spin stiffness and spin-wave velocity characterizing the low-energy magnons in the Néel phase.