Quantum Dynamics Of Bose Particles In Double Potential Well

With the development of quantum information,micro-well technology,quantum manipulation technology,laser technology,etc.,the Bose-Hubbard model,which is wildly used to describe the Bose-Einstein condensate(BEC),is a typical and the interacting many-body system for studying various quantum effects.Those effects play an important role in quantum information science and technology.In this work,we consider the Bose-Hubbard model that describes the quantum dynamics of Bose particles without spin in an asymmetric double-potential well.The influence of the coupling interaction and the potential energy deviation between two wells on the time evolution of some physical quantities is presented.Those quantities include the particle number difference,the linear entropy,the norm,and the relative entropy,where the linear entropy is the measure of entanglement for pure states,and the norm and the relative entropy are the recently proposed measures of quantum coherence.The calculated results reveal that for the given initial state and specific interaction,the coupling interaction and the existence of potential energy deviations between two wells cause the particle number difference between two wells to collapse and recover over time.When the coupling and the potential energy deviation between two wells reach a certain value,the tunneling effect occurs between two wells,dynamical entanglement and coherence are generated.Under the suitable initial state,as the coupling interaction increases,the maximal entanglement and the maximal coherence become larger,whereas the maximal entanglement and the maximal coherence become smaller if the deviation of the potential energy between two wells increases.That means that the entanglement and the coherence can be destroyed.What is more,we study the dynamical properties of the Bose-Hubbard model for spin-1 particles in two wells,where our focus is paid on the effect of the spin interaction between particles on those quantities.For the given model parameters,increasing the spin interaction between particles,the phenomenon of collapse and recovery for the particle number difference changes,and the maximal entanglement and the maximal coherence gradually decrease.When the spin interaction reaches a certain value,the collapse and recovery phenomena can disappear,and the entanglement and the coherence are destroyed.In summary,we have studied the quantum dynamics of Bose particles in the double potential well,showing that different model parameters can affect the dynamical behavior of entanglement and coherence for initial states,which suggests that we can adjust quantum entanglement and coherence through model parameters.Additionally,the dynamical entanglement and the dynamical coherence nicely display the same trend.In future work,we will explore dynamical properties of other initial states in various models and discuss their possible applications in quantum information.