Influence Of Periodic Driven On Dynamics Of Bose-Einstein Condensates

Bose-Einstein condensation(BEC) is a phenomenon of macroscopic occupation in quantum ground state by a large number of identical bosons when the temperature of the system below a critical temperature.BEC is one of the most basic theory in quantum statistic mechanics and the foundation of superconductivity and superfluidity.BEC theory is also the physical root of many kinds of macroscopic quantum phenomena.The research of BEC is a ubiquitous phenomenon relating to many fields in physics,such as atomic and molecular physics,quantum optics,nuclear physics,statistical physics and condensate matter physics,astrophysics,and hence has significant importance in the theoretical viewpoint.It is also has promising future prospects in practical application. Therefore the investigation of the BEC became a focus field to the Physical scientists.In this thesis,by using the mean-filed method we investigate the influence of periodic driven on dynamics of Bose-Einstein condensation and obtain a serial of valuable results.The thesis consists of four chapters:In chapter one,we mainly introduce the history of BEC research and application,the experiments technologies of realizing BEC,the condensation of non-interaction Bose gas and the mean-filed theory;In chapter two,we derivate the canonical form of quantum system and the dynamical equation of BEC in the driven two-well,then,we study the dynamics of their phase space of BEC under periodic driving force;In older to extending our study to more interesting many-component system,In chapter three,we first give the theoretical model of a BEC in a triple-well trap,and then study energy levels structure of the BEC and found energy levels structure are very implicate,and finally we discuss the dynamics of a BEC in a tilted triple-well trap under a periodic external driving force;In the final chapter,we summarize the main results of the present paper.