Study on Mott-Insulator-Superfluid Phase Transition in Symmetric and Unsymmetric Double-Chain Bose-Hubbard Model  

作　　者：Rongsheng Han Zhihong Liu Liang Chen Jialu Fu 

机构地区：[1]Mathematics and Physics Department,North China Electric Power University

出　　处：《Journal of Harbin Institute of Technology(New Series)》2019年第1期61-67,共7页哈尔滨工业大学学报（英文版）

基　　金：Sponsored by the National Natural Science Foundation China(Grant No.11504106);the Special Foundation for Theoretical Physics Research Program of China(Grant No.11447167)

摘　　要：The symmetric and the asymmetric double-chain Bose-Hubbard Models( BHMs) are studied by the mean-field theory. By using Landau's quantum phase transition theory,phase diagrams for systems with different hopping energies and repulsive interactions are obtained. Thereby,Mott-insulator-superfluid( MISF)phase transition boundaries are determined. Our results show that tunneling effects between two chains provide additional channels for particles hopping between corresponding optical lattice sites of different chains,which makes easier for systems to transit from MI to SF phase. The two-site parity function is also utilized to investigate the properties of the system near the quantum phase transit point.We found that the increase of inter-chain hopping will reinforce the tunneling effects between two chains,and reduce the intrachain tunneling effects within the same chain.The symmetric and the asymmetric double-chain Bose-Hubbard Models( BHMs) are studied by the mean-field theory. By using Landau's quantum phase transition theory,phase diagrams for systems with different hopping energies and repulsive interactions are obtained. Thereby,Mott-insulator-superfluid( MISF)phase transition boundaries are determined. Our results show that tunneling effects between two chains provide additional channels for particles hopping between corresponding optical lattice sites of different chains,which makes easier for systems to transit from MI to SF phase. The two-site parity function is also utilized to investigate the properties of the system near the quantum phase transit point.We found that the increase of inter-chain hopping will reinforce the tunneling effects between two chains,and reduce the intrachain tunneling effects within the same chain.

关 键 词：Bose-Hubbard model MOTT Insulator-Superfluid Phase Transition LANDAU theory 

分 类 号：O469[理学—凝聚态物理]