2025/06/27 by Williams, Fletcher, Dahlbom, David, Zhang, Hao +3 · 2 citations
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.2506.22320
Magnetic skyrmions are topologically protected solitons observed in various classes of real magnets. In two-dimensional systems, where the target space of local magnetization values is the two-sphere S2, skyrmion textures are classified by the homotopy classes of two-loops S2 in S2: Π2(S2) ≅ Z. Here, we demonstrate that more general topological skyrmion textures emerge in the classical limit of quantum dimer systems, where the phase space of the relevant classical theory is \mathbbCPN-1 (with N=4 for the case of interest), because the relevant second homotopy group, Π2(\mathbbCPN-1) ≅ Z for N≥ 2, remains unchanged. Building on the framework established by Zhang et al. (2023), we consider a classical limit based on SU(4) coherent states, which preserve intra-dimer entanglement. We show that the zero-temperature phase diagram of frustrated spin-dimer systems on a bilayer triangular lattice with weak inter-dimer coupling includes two magnetic-field-induced \mathbbCP3 skyrmion crystal phases.