From Chiral Spin Liquid to Skyrmion Lattices

H. D. ROSALES; F. A. GÓMEZ ALBARRACÍN; P. PUJOL; L. JAUBERT

Temuco (Virtual)

Congreso; 16 th International Seminar on Condensed Matter and Statistical Physics; 2021

(Charla) In recent years, systems with topological excitations have been a subject of constant research in condensed matter. In this context appear magnetic skyrmions [1] and merons [2], which are vortex-like magnetic textures with particle-like properties. These objects, whose typical size is of a few hundred nanometers, have become promising candidates for future spintronic applications such as racetrack memories [3]. Under certain circumstances, skyrmions can be arranged in periodic arrays or lattices whose nature admits two types of interpretation: either as an agglomeration of quasi-particles arranged in a compact geometry, or as a coherent superposition of spin helices. This double interpretation gives rise to one important issue: how does a skyrmion lattice crystallize?. In this work, we explore the occurrence and thermal stability of skyrmions in a chiral spin liquid background as a precursor to isolated skyrmions, and its subsequent crystallization. First, using large-scale Monte Carlo simulations, we show that the combined effect of antisymmetric interactions and macroscopic degeneration induces a large variety of topologically non-trivial phases including bimerons, skyrmions, skyrmion liquids and chiral spin liquids. Finally, we show that the crystallization process of skyrmions has the characteristics presented in the KTHNY theory [4,5,6].[1] S. Muhlbauer, et al., Science, 323, 915 (2009).[2] S. Gao, H.D. Rosales, F.A. Gómez Albarracı́n, et al., Nature, 586, 37, (2020).[3] B.Gobel, A.F. Schaffer, J. Berakdar, et al., Sci. Rep., 9, 12119, (2019).[4] B. I. Halperin, D. R. Nelson, Phys. Rev. Lett., 41, 121, (1978).[5] D. R. Nelson, B. I. Halperin, Phys. Rev. B, 19, 2457, (1979).[6] A. P. Young, Phys. Rev. B 19, 1855 (1979).