Clustering of spins on Ising and Heisenberg models on kagome and pyrochlore lattices

Date

Jan 30, 2018

Time

2:00 PM - 3:00 PM

Speaker

Tomonari Mizoguchi

Affiliation

Gakushuin University

Language

en

Main Topic

Physik

Other Topics

Physik

Description

Fractionalization is one of the fundamental properties of topological phases. For example, in a spin ice, an emergent fractionalized degrees of freedom is called a magnetic monopole [1], which is a topological defect on top of a spin-ice manifold. In the present work, we investigate the many-body effects of such topological charges that emerge in classical spin liquids on corner-sharing lattices such as kagome and pyrochlore lattices. In the first part of my talk, I will show the thermodynamic properties of a J1-J2-J3 Ising model on a kagome lattice [2], where J2 and J3 give rise to the nearest-neighbor interaction between topological charges. We find that the interactions between topological charges give rise to a novel classical spin liquid state characterized by the formation of clusters, or “hexamers”, of same-sign topological charges. Then, in the second part, I will show the results for J1-J2-J3 Heisenberg models on kagome and pyrochlore lattices [3]. Using a large-N approximation and Monte Carlo simulations, we elucidate the static structure factors, and find that the obtained patterns are very similar to those in Ising models. This indicates that the short-range correlations similar to topological-charge clusters develop even in the Heisenberg model. [1] C. Castelnovo, R. Moessner, and S. L. Sondhi, Nature (London) 451, 42 (2008). [2] T. M., L. D. C. Jaubert, and M. Udagawa, PRL 119, 077207 (2017). [3] T. M., L. D. C. Jaubert, and M. Udagawa, in preparation.

Last modified: Jan 30, 2018, 8:42:34 AM