We present numerical evidence for the crystallization of magnons below the saturation field at non-zero temperatures for the highly frustrated spin-half kagome Heisenberg antiferromagnet. This phenomenon can be traced back to the existence of independent localized magnons or equivalently flat-band multi-magnon states. We present a loop-gas description of these localized magnons and a phase diagram of this transition, thus providing information for which magnetic fields and temperatures magnon crystallization can be observed experimentally. The emergence of a finite-temperature continuous transition to a magnon-crystal is expected to be generic for spin models in dimension D>1 where flat-band multi-magnon ground states break translational symmetry.
@article{arxiv.1910.10448,
title = {Magnon crystallization in the kagome lattice antiferromagnet},
author = {J. Schnack and J. Schulenburg and A. Honecker and J. Richter},
journal= {arXiv preprint arXiv:1910.10448},
year = {2020}
}
Comments
7 pages, 6 figures; replacement of v2, since supplement was not correctly attached