Effects Of Two-site Potential Difference On The Inter-mode Correlation In Bose-Hubbard Model

In this paper,the Bose-Hubbard model is used to describe the boson subsystems bound in the asymmetric double-potential well.The influence of the potential difference on the evolution of the physical quantities is studied.Firstly the evolution law of the population imbalance in the two-mode Bose-Hubbard model is investigated.The influence of initial states,potential difference between the two wells,coupling constant for the one-site atom-atom interaction,single atom tunneling amplitude on the population imbalance evolution are explored.We find that when in a certain parameter value and a specific initial state and combination with the evolution of the tunneling and the current between wells.We can find that the existence of the potential difference between the two wells make the evolution of the population imbalance in the two wells show a collapse and recovery phenomena.When the potential difference between the two wells is large enough,the system will appear self-trapping.The coherence of the system is also studied.Under certain initial states and parameters,the increase of the potential deviation between the wells will destroy the coherence of the system.Secondly,according to the Cauchy-Schwartz,we investigate the influence of the potential difference between the two wells on the nonclassical correlation of the model.When the initial state is SU(2),within a certain range of parameters,increasing the potential difference between the two wells can increase the degree of nonclassical correlation between modes.Finally,based on the Hillery-Zubairy entanglement criterion,we study the influence of the potential difference of the two wells on the entanglement evolution of the model.When the initial state is SU(2),if the potential difference is zero,QE(?)is always less than zero,the system may maintains a good entanglement property.And if the potential difference of the wells exists,QE(r)is not always less than zero,and the entanglement properties of the system become complicated.