Variational study of triangular lattice spin-1/2 model with ring exchanges and spin liquid state in κ-(ET)2Cu2(CN)3 -: art. no. 045105
Variational study of triangular lattice spin-1/2 model with ring exchanges and spin liquid state in κ-(ET)2Cu2(CN)3 -: art. no. 045105
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DOI：
10.1103/physrevb.72.045105
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发表时间：
2005-07-01
影响因子：
3.7
通讯作者：
Motrunich, OI
中科院分区：
文献类型：
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作者：
Motrunich, OI
利用变分法研究了具有反铁磁海森堡和环交换的自旋为1/2的三角晶格系统，重点讨论了自旋液体态的可能实现。试验自旋液体波函数得到的费米平均场状态的Gutzwiller投影和它们的能量与磁有序的试验状态进行了比较。我们发现，在一定范围内的环交换耦合后破坏反铁磁秩序，最好的这种自旋液体状态本质上是一个Gutzwiller投影费米海状态。我们提出这种具有自旋费米表面的自旋液体作为在有机化合物kappa-（ET）（2）Cu-2（CN）（3）中观察到的绝缘相的候选物，并描述了这一提议的一些实验结果。
We study triangular lattice spin-1/2 system with antiferromagnetic Heisenberg and ring exchanges using variational approach focusing on possible realization of spin-liquid states. Trial spin liquid wave functions are obtained by Gutzwiller projection of fermionic mean-field states and their energetics is compared against magnetically ordered trial states. We find that in a range of the ring exchange coupling upon destroying the antiferromagnetic order, the best such spin liquid state is essentially a Gutzwiller-projected Fermi sea state. We propose this spin liquid with a spinon Fermi surface as a candidate for the nonmagnetic insulating phase observed in the organic compound kappa-(ET)(2)Cu-2(CN)(3), and describe some experimental consequences of this proposal.