The effects of the Dzyaloshinskii-Moriya interaction on the ground-state properties of the XY chain in a transverse field  

作　　者：钟鸣 徐卉 刘小贤 童培庆 

机构地区：[1]Department of Physics and Institute of Theoretical Physics,Nanjing Normal University [2]Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems,Nanjing Normal University

出　　处：《Chinese Physics B》2013年第9期285-291,共7页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 11205090 and 11175087);the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (Grant No. 12KJB140008)

摘　　要：The effects of the Dzyaloshinski-Moriya （DM） interaction on the ground-state properties of the anisotropic XY chain in a transverse field have been studied by means of correlation functions and entanglement. Different from the case without the DM interaction, the excitation spectra ek of this model are not symmetrical in the momentum space and are not always positive. As a result, besides the ferromagnetic （FM） and the paramagnetic （PM） phases, a gapless chiral phase is induced. In the chiral phase, the von Neumann entropy is proportional to log2 L （L is the length of a subchain） with the coefficient A ~ 1/3, which is the same as that of the XY chain in a transverse field without the DM interaction for 7 = 0 and 0 〈 h 〈 1. And in the vicinity of the critical point between the chiral phase and the FM （or PM） phase, the behaviors of the nearest- neighbor concurrence and its derivative are like those for the anisotropy transition.The effects of the Dzyaloshinski-Moriya （DM） interaction on the ground-state properties of the anisotropic XY chain in a transverse field have been studied by means of correlation functions and entanglement. Different from the case without the DM interaction, the excitation spectra ek of this model are not symmetrical in the momentum space and are not always positive. As a result, besides the ferromagnetic （FM） and the paramagnetic （PM） phases, a gapless chiral phase is induced. In the chiral phase, the von Neumann entropy is proportional to log2 L （L is the length of a subchain） with the coefficient A ~ 1/3, which is the same as that of the XY chain in a transverse field without the DM interaction for 7 = 0 and 0 〈 h 〈 1. And in the vicinity of the critical point between the chiral phase and the FM （or PM） phase, the behaviors of the nearest- neighbor concurrence and its derivative are like those for the anisotropy transition.

关 键 词：Dzyaloshinskii-Moriya interaction the XY chain in a transverse field quantum entanglement ground-state properties 

分 类 号：O431.2[机械工程—光学工程]