Block Entanglement in the Single-Hole Hubbard Model  

作　　者：姚凯伦 孙效中 刘祖黎 李彦超 喻莉 高国营 

机构地区：[1]Department of Physics, Huazhong University of Science and Technology, Wuhan 430074 [2]The International Centre of Materials Physics, Chinese Academy of Sciences, Shenyang 110015

出　　处：《Chinese Physics Letters》2006年第9期2352-2355,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant No 10574048.

摘　　要：We investigate the distribution of the entanglement of the one-dimensional single-hole Hubbard model （HM） and study the relationship between the entanglement and quantum phase transition in the model. The von Neumann entropy of a block with neighbouring spins L for a single-hole HM is calculated using the densitymatrix renormalization group. The distributions of the entanglement entropy in the ground state, as a function of block length, show a dramatic effect, i.e. effectively decoupling with the centres, no matter how the Coulomb interaction u 〉0 or u 〈0. Contrarily, for the Coulomb interaction u = 0 or close to zero, the entanglement entropy in the single-hole model reaches a saturation value for a certain block size. For a fixed size L = 40, the ground state entanglement entropy measure, as a function of u1 shows a peak corresponding to the critical quantum phase transition.We investigate the distribution of the entanglement of the one-dimensional single-hole Hubbard model （HM） and study the relationship between the entanglement and quantum phase transition in the model. The von Neumann entropy of a block with neighbouring spins L for a single-hole HM is calculated using the densitymatrix renormalization group. The distributions of the entanglement entropy in the ground state, as a function of block length, show a dramatic effect, i.e. effectively decoupling with the centres, no matter how the Coulomb interaction u 〉0 or u 〈0. Contrarily, for the Coulomb interaction u = 0 or close to zero, the entanglement entropy in the single-hole model reaches a saturation value for a certain block size. For a fixed size L = 40, the ground state entanglement entropy measure, as a function of u1 shows a peak corresponding to the critical quantum phase transition.

关 键 词：QUANTUM RENORMALIZATION-GROUPS PHASE-TRANSITION ENTROPY 

分 类 号：O413[理学—理论物理]