Chillal Shravani, Iqbal Yasir, Jeschke Harald O, Rodriguez-Rivera Jose A, Bewley Robert, Manuel Pascal, Khalyavin Dmitry, Steffens Paul, Thomale Ronny, Islam A T M Nazmul, Reuther Johannes, Lake Bella
Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner Platz 1, 14109, Berlin, Germany.
Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India.
Nat Commun. 2020 May 11;11(1):2348. doi: 10.1038/s41467-020-15594-1.
The quantum spin liquid is a highly entangled magnetic state characterized by the absence of static magnetism in its ground state. Instead, the spins fluctuate in a highly correlated way down to the lowest temperatures. Quantum spin liquids are very rare and are confined to a few specific cases where the interactions between the magnetic ions cannot be simultaneously satisfied (known as frustration). Lattices with magnetic ions in triangular or tetrahedral arrangements, which interact via isotropic antiferromagnetic interactions, can generate such a frustration. Three-dimensional isotropic spin liquids have mostly been sought in materials where the magnetic ions form pyrochlore or hyperkagome lattices. Here we present a three-dimensional lattice called the hyper-hyperkagome that enables spin liquid behaviour and manifests in the compound PbCuTeO. Using a combination of experiment and theory, we show that this system exhibits signs of being a quantum spin liquid with no detectable static magnetism together with the presence of diffuse continua in the magnetic spectrum suggestive of fractional spinon excitations.
量子自旋液体是一种高度纠缠的磁态，其基态的特征是不存在静态磁性。相反，自旋以高度相关的方式波动，直至最低温度。量子自旋液体非常罕见，仅限于少数几种特定情况，即磁性离子之间的相互作用无法同时满足（称为阻挫）。具有三角形或四面体排列的磁性离子的晶格，通过各向同性反铁磁相互作用相互作用，可以产生这种阻挫。三维各向同性自旋液体大多在磁性离子形成焦绿石或超 kagome 晶格的材料中寻找。在这里，我们展示了一种称为超超 kagome 的三维晶格，它能够实现自旋液体行为，并在化合物 PbCuTeO 中表现出来。通过实验和理论相结合，我们表明这个系统表现出是一种量子自旋液体的迹象，没有可检测到的静态磁性，同时在磁谱中存在漫射连续体，暗示着分数自旋子激发。
