Magnetic-field-induced condensation of triplons in Han Purple pigment BaCuSi2O6 -: art. no. 087203
Magnetic-field-induced condensation of triplons in Han Purple pigment BaCuSi2O6 -: art. no. 087203
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DOI：
10.1103/physrevlett.93.087203
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发表时间：
2004-08-20
影响因子：
8.6
通讯作者：
Uchinokura, K
中科院分区：
文献类型：
--
作者：
Jaime, M;Correa, VF;Uchinokura, K
BaCuSi_2O_6是一种古老的颜料，同时也是一种准二维磁性绝缘体，具有带隙的自旋二聚体基态。强磁场的应用关闭了这个间隙，产生了玻色子自旋三重态激发的气体。自旋晶格的拓扑结构使得BaCuSi 2 O 6成为研究三重态激发的玻色-爱因斯坦凝聚作为外部磁场的函数的理想候选者，该外部磁场充当化学势。与量子Monte Carlo数值模拟一致，我们观察到一个独特的lambda异常的比热连同最大的磁化率冷却到液氦温度时。
Besides being an ancient pigment, BaCuSi2O6 is a quasi-2D magnetic insulator with a gapped spin dimer ground state. The application of strong magnetic fields closes this gap, creating a gas of bosonic spin triplet excitations. The topology of the spin lattice makes BaCuSi2O6 an ideal candidate for studying the Bose-Einstein condensation of triplet excitations as a function of the external magnetic field, which acts as a chemical potential. In agreement with quantum Monte Carlo numerical simulations, we observe a distinct lambda anomaly in the specific heat together with a maximum in the magnetic susceptibility upon cooling down to liquid helium temperatures.