2019/10/30 by N. J. Laurita, A. Ron, Laurita, N. J. +28
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #FOS: Physical sciences #Multiferroics and related materials #Physics of Superconductivity and Magnetism #Strongly Correlated Electrons (cond-mat.str-el) #cond-mat.str-el
paper · pdf · doi:10.48550/arxiv.1910.13606
13 pages main text, 4 figures, 10 pages supplementary information
arxiv created 2019/10/30 · openalex publication_date 2019/10/30 · arxiv updated 2019/10/31 · openalex created_date 2019/11/08 · openalex updated_date 2026/07/28
Nearest-neighbor interacting S = 1/2 spins on the ideal Kagomé lattice are predicted to form a variety of novel quantum entangled states, including quantum spin-liquid (SL) and valence bond solid (VBS) phases. In real materials, the presence of additional perturbative spin interactions may further expand the variety of entangled states, which recent theoretical analyses show are identifiable through the spontaneous loss of particular discrete point group symmetries. Here we comprehensively resolve the ground state point group symmetries of the prototypical Kagomé SL candidate ZnCu3(OH)6Cl2 (Herbertsmithite) using a combination of optical ellipsometry and wavelength-dependent multi-harmonic optical polarimetry. We uncover a subtle parity breaking monoclinic structural distortion at a temperature above the nearest-neighbor exchange energy scale. Surprisingly, the parity-breaking order parameter is dramatically enhanced upon cooling and closely tracks the build-up of nearest-neighbor spin correlations, suggesting that it is energetically favored by the SL state. The refined low temperature symmetry group greatly restricts the number of viable ground states, and, in the perturbative limit, points toward the formation of a nematic Z2 striped SL ground state - a SL analogue of a liquid crystal.