摘要
Ground-state(GS)properties of the two-dimensional(2D)quantum compass model in an external field on a square 5×5 lattice are investigated by using the exact diagonalization(ED)method.We obtain the GS energy and evaluate quantities such as its correlation functions,nearest-neighbor entanglement and local order parameter.As the external field is presented,the first-order quantum phase point is absent and the system exhibits the behaviors of the second-order phase transition.
作者
SUN Ke-Wei
CHEN Qing-Hu
孙科伟;陈庆虎(School of Science,Hangzhou Dianzi University,Hangzhou 310018;Department of Physics,Zhejiang University,Hangzhou 310027)
基金
by the National Natural Science Foundation of China,PCSIRT in University in China(No IRT0754)
the National Basic Research Program of China under Grant No 2009CB929104.
