Supersolid phase and magnetization plateaus observed in the anisotropic spin-3/2 Heisenberg model on bipartite lattices
Supersolid phase and magnetization plateaus observed in the anisotropic spin-3/2 Heisenberg model on bipartite lattices
复制标题
在二分晶格的各向异性自旋 3/2 海森堡模型中观察到的超固相和磁化平台
DOI：
10.1103/physrevb.84.184427
复制
发表时间：
2011
影响因子：
3.7
通讯作者：
K. Penc
中科院分区：
文献类型：
--
作者：
J. Romhányi;F. Pollmann;K. Penc
我们研究了自旋为3/2的海森堡模型，包括一维和二维的易平面和交换各向异性。在伊辛极限下，当非对角交换相互作用J为零时，磁场中的相图的特征在于磁化平台，该磁化平台要么是非线性不变的，要么具有两个子晶格顺序，具有宏观退化的相边界。使用现场因式分解变分波函数和微扰扩展周围的伊辛极限，我们发现，超流和超固相之间出现的高原小的有限值J的变分方法是补充的密度矩阵重整化群研究的一维链和精确的对角化计算的小集群的正方形晶格。所研究的模型可以作为层状Ba 2CoGe 2 O 7材料化合物的最小模型，并且我们相信，在模型参数空间中的均匀1/3平台附近可以观察到测量的磁化曲线中的异常。
We study the spin-3/2 Heisenberg model including easy-plane and exchange anisotropies in one and two dimensions. In the Ising limit, when the off-diagonal exchange interaction J is zero, the phase diagram in magnetic field is characterized by magnetization plateaus that are either translationally invariant or have a two-sublattice order, with phase boundaries that are macroscopically degenerate. Using a site factorized variational wave function and perturbational expansion around the Ising limit, we find that superfluid and supersolid phases emerge between the plateaus for small finite values of J. The variational approach is complemented by a Density Matrix Renormalization Group study of a one-dimensional chain and exact diagonalization calculations on small clusters of a square lattice. The studied model may serve as a minimal model for the layered Ba2CoGe2O7 material compound, and we believe that the vicinity of the uniform 1/3 plateau in the model parameter space can be observed as an anomaly in the measured magnetization curve.