Gapped Spin-1/2 Spinon Excitations in a New Kagome Quantum Spin Liquid Compound Cu_3Zn(OH)_6FBr  

作　　者：冯子力 李政 孟鑫 衣玮 魏源 张骏 王艳成 蒋伟 刘峥 李世燕 刘锋 雒建林 李世亮 郑国庆 孟子杨 梅佳伟 石友国 

机构地区：[1]Institute of Physics, Chinese Academy of Sciences [2]School of Physical Sciences, University of Chinese Academy of Sciences [3]State Key Laboratory of Surface Physics, Department of Physics, and Laboratory of Advanced Materials, Fudan University [4]Department of Materials Science and Engineering, University of Utah [5]Institute for Advanced Study,Tsinghua University [6]Collaborative Innovation Center of Advanced Microstructures [7]Collaborative Innovation Center of Quantum Matter [8]Department of Physics, Okayama University [9]Institute for Quantum Science and Engineering, and Department of Physics, Southern University of Science and Technology [10]Beijing Computational Science Research Center

出　　处：《Chinese Physics Letters》2017年第7期249-253,共5页中国物理快报（英文版）

基　　金：Supported by the National Key Research and Development Program of China under Grant Nos 2016YFA0300502,2016YFA0300503,2016YFA0300604,2016YF0300300 and 2016YFA0300802;the National Natural Science Foundation of China under Grant Nos 11421092,11474330,11574359,11674406,11374346 and 11674375;the National Basic Research Program of China(973 Program)under Grant No 2015CB921304;the National Thousand-Young-Talents Program of China;the Strategic Priority Research Program(B) of the Chinese Academy of Sciences under Grant Nos XDB07020000,XDB07020200 and XDB07020300;supported by DOE-BES under Grant No DE-FG02-04ER46148

摘　　要：We report a new kagome quantum spin liquid candidate CuaZn（OH）6FBr, which does not experience any phase transition down to 50inK, more than three orders lower than the antiferromagnetic Curie-Weiss temperature （-200 K）. A clear gap opening at low temperature is observed in the uniform spin susceptibility obtained from 19F nuclear magnetic resonance measurements. We observe the characteristic magnetic field dependence of the gap as expected for fractionalized spin-1/2 spinon excitations. Our experimental results provide firm evidence for spin fractionalization in a topologically ordered spin system, resembling charge fraetionalization in the fractional quantum Hall state.We report a new kagome quantum spin liquid candidate CuaZn（OH）6FBr, which does not experience any phase transition down to 50inK, more than three orders lower than the antiferromagnetic Curie-Weiss temperature （-200 K）. A clear gap opening at low temperature is observed in the uniform spin susceptibility obtained from 19F nuclear magnetic resonance measurements. We observe the characteristic magnetic field dependence of the gap as expected for fractionalized spin-1/2 spinon excitations. Our experimental results provide firm evidence for spin fractionalization in a topologically ordered spin system, resembling charge fraetionalization in the fractional quantum Hall state.

关 键 词：OH Gapped Spin-1/2 Spinon Excitations in a New Kagome Quantum Spin Liquid Compound Cu3Zn Cu 

分 类 号：O469[理学—凝聚态物理]