Z_2 topological number of local quantum clusters in the orthogonal dimer model
Z_2 topological number of local quantum clusters in the orthogonal dimer model
复制标题
正交二聚体模型中局域量子簇的拓扑数Z_2
DOI：
10.1088/1742-6596/320/1/012019
复制
发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Y.Hatsugai
中科院分区：
文献类型：
--
作者：
I.Maruyama;S.Tanaya;M.Arikawa;Y.Hatsugai
We have studied the Z 2 topological number defined by the Berry phase for the gapped frustrated systems including the orthogonal dimer model which has a direct product state of local quantum clusters as the exact ground state. The Z 2 topological number can clarify what kind of the local quantum clusters is formed to lift the macroscopic degeneracy due to frustration, even when the exact ground state is unknown. As a demonstration, the dimer-singlet and plaquette-singlet phase are identified by two kinds of Z 2 topological numbers in the Shastry-Sutherland model and its generalization realized experimentally as SrCu 2 (BO 3) 2 and CaV 4 O 9.
