Kinetic kagome magnetism: from self-trapping RVB polarons to semiclassical correlations

Abstract

To gain deeper insight into the role of hole kinetics in determining magnetism in highly frustrated doped Mott insulators, we consider the single-hole counter-Nagaoka problem on the kagome lattice, using magnetization as a tuning parameter. Near full polarization, a doped hole delocalizes upon binding reversed spins in a pattern of singlet bonds which we term resonating-valence-bond (RVB) polaron. These RVB polarons can have extremely small effective bandwidths, and hence exhibit self-trapping. By tuning the spin polarization, we track the evolution of these states toward the unpolarized sector, where we observe the emergence of $\sqrt{3}\times\sqrt{3}$ antiferromagnetic correlation reminiscent of the classical Potts and Heisenberg models on the kagome lattice. These results provide a framework to understand how RVB physics at short scales evolves into conventional magnetic correlations at long scales.