Replica symmetry breaking in the RKKY skyrmion crystal system
Abstract
We study the RKKY Heisenberg model on a three-dimensional stacked-triangular lattice under magnetic fields by extensive Monte Carlo simulations to get insight into the chiral-degenerate symmetric skyrmion crystal (SkX) in centrosymmetric metallic magnets. The triple- SkX state and the double- states are realized, together with the single- state. We find an unexpected phenomenon of the replica-symmetry breaking (RSB) well-known in glassy systems, although the Hamiltonian and the ordered state are entirely regular. In the RSB SkX phase, the triple- SkX state macroscopically coexists with the single- state, in spite of the fact that these ordered states cannot be transformed via any Hamiltonian-symmetry operation. In the thermodynamic limit, the free energies of these states are degenerate whereas the free-energy barrier between the states diverges, breaking the ergodicity. A similar RSB is observed also in the RSB double- phase where the double- state macroscopically coexists with the single- state. Experimental implications are discussed.
Keywords
Cite
@article{arxiv.2108.11585,
title = {Replica symmetry breaking in the RKKY skyrmion crystal system},
author = {Kota Mitsumoto and Hikaru Kawamura},
journal= {arXiv preprint arXiv:2108.11585},
year = {2021}
}
Comments
19 pages, 22 figures