Soft acoustic modes in the two-dimensional spin system SrCu2(BO3)(2).
Soft acoustic modes in the two-dimensional spin system SrCu2(BO3)(2).
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二维自旋系统 SrCu2(BO3)(2) 中的软声学模式。
DOI：
10.1103/physrevlett.86.4847
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发表时间：
2001
影响因子：
8.6
通讯作者：
Y. Ueda
中科院分区：
文献类型：
--
作者：
B. Wolf;S. Zherlitsyn;S. Schmidt;B. Lüthi;H. Kageyama;Y. Ueda
SrCu2(BO3)(2)是一个接近量子临界点的二维二聚化量子自旋体系。纵向和横向声模的声速表现出很强的自旋晶格效应。剪切c(66)模随温度的变化表现出4.5%的显著软化，在50T以下的磁场中软化超过25%。这种巨大的影响发生在m/m(0)=1/4和1/3的磁化平台附近。我们可以用交换伸缩机制定量地分析所有测得的弹性模c(11)、c(44)和c(66)的温度依赖性。具有B(2g)对称性的软c(66)模使我们能够预测凝聚三重态在某些高原上可能的对称性。
SrCu2(BO3)(2) is a two-dimensional dimerized quantum spin system which is close to a quantum critical point. The sound velocity for the longitudinal and transverse acoustic modes shows strong spin-lattice effects. The shear c(66) mode exhibits a pronounced softening of 4.5% as a function of temperature and softens more than 25% in fields up to 50 T. This huge effect occurs in the vicinity of the magnetization plateaus m/m(0) = 1/4 and 1/3. We can analyze quantitatively the temperature dependence of all measured elastic modes c(11), c(44), and c(66) with an exchange striction mechanism. The soft c(66) mode with B(2g) symmetry enables us to predict the possible symmetry of the condensed triplets in some plateaus.