Dimer liquid state in the quantum antiferromagnet compound LiCu 2 O 2
Dimer liquid state in the quantum antiferromagnet compound LiCu 2 O 2
复制标题
量子反铁磁体化合物LiCu 2 O 2 中的二聚体液态
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
J. Crow
中科院分区：
文献类型：
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作者：
S. Zvyagin;G. Cao;Y. Xin;S. McCall;T. Caldwell;W. Moulton;L. Brunel;A. Angerhofer;J. Crow
系统的结构，磁性，电子自旋共振，和比热研究的S=½量子反铁磁体化合物LiCu 2 O2的结果。在T = 23 K以上的温度下，发现了自旋单重态基态.在这个温度范围内，LiCu 2 O2可以被看作是一个量子链S= 1/2，在J2/J1比值的中间范围内（α c1 <J2/J1 <α c2），最近邻和次最近邻相互作用相互竞争。自旋单重态基态和第一激发三重态之间的能隙Δ为1.72K。该研究证实了LiCu 2 O2中的磁相变，该相变导致自旋单重基态在低于23 K的温度下崩溃此外，在T = 9 K处还发现了第二次低温相变。讨论了LiCu 2 O2二聚体相的磁激发谱的特殊性及其磁结构。
Results of systematic structural, magnetic, electron-spin resonance, and specific-heat investigations of the S=½ quantum antiferromagnet compound LiCu 2 O 2 are presented. A spin-singlet ground state is revealed at temperatures above T∼23 K. In this temperature region LiCu 2 O 2 may be regarded as a quantum S= ½ chain with competing nearest- and next-nearest-neighbor interactions in the intermediate range of the J 2 /J 1 ratio (α c 1 <J 2 /J 1 <α c 2 ). The size of the energy gap between the spin-singlet ground state and the first excited triplet, Δ, is found to be ∼72 K. The study confirms a magnetic phase transition in LiCu 2 O 2 , which results in the collapse of the spin-singlet ground state at a temperature below 23 K. In addition, a second low-temperature transition was found at T∼9 K. Peculiarities of the magnetic excitation spectrum in the dimer phase of LiCu 2 O 2 and its magnetic structure are discussed.