Magnetic Excitations of a quantum spin liquid candidate based on a triangulated kagome lattice

The two-dimensional (2D) Triangulated Kagome Lattice (TKL) is related to the conventional kagome lattice but with additional ‘triangles within the triangles’. There are several theoretical investigations of this lattice including one which suggests that the triangulated kagome lattice with antiferromagnetic interactions could be the most frustrated lattice yet discovered. The metal organic framework compound, Cu9Cl2(cpa)6·42D2O, is the only known physical realization of this lattice where the magnetic Cu2+ ions have quantum spin=1/2. No long-range magnetic order was observed down to T=0.05K despite a large antiferromagnetic Curie-Weiss temperature of ~250K suggesting strong frustration. In this proposal we request to investigate the magnetic excitations spectrum of this compound.

二维（2D）三角化Kagome晶格（TKL）与传统Kagome晶格相关，但在三角形内部额外包含“嵌套三角形”结构。已有多项理论研究针对该晶格展开，其中一项研究指出，具有反铁磁相互作用（antiferromagnetic interactions）的三角化Kagome晶格可能是目前已发现的受挫程度最高的晶格（frustrated lattice）。金属有机框架化合物（metal organic framework compound）Cu₉Cl₂(cpa)₆·42D₂O是该晶格唯一已知的物理实现，其磁性Cu²⁺离子的量子自旋（quantum spin）为1/2。尽管该化合物的反铁磁居里-外斯温度（Curie-Weiss temperature）高达约250K（表明存在强烈的受挫效应），但在温度低至0.05K时仍未观测到长程磁有序（long-range magnetic order）。