Shchesnovich V S, Konotop V V
Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, SP, 09210-170 Brazil.
Phys Rev Lett. 2009 Feb 6;102(5):055702. doi: 10.1103/PhysRevLett.102.055702. Epub 2009 Feb 4.
It is shown that bifurcation of the mean-field dynamics of a Bose-Einstein condensate can be related to the quantum phase transition of the original many-body system. As an example we explore the intraband tunneling in the two-dimensional optical lattice. Such a system allows for easy control by the lattice depth as well as for macroscopic visualization of the phase transition. The system manifests switching between two self-trapping states or from a self-trapping state to a superposition of the macroscopically populated self-trapping states with a steplike variation of the control parameter about the bifurcation point. We have also observed the magnification of the microscopic difference between the even and odd number of atoms to a macroscopically distinguishable dynamics of the system.
结果表明，玻色 - 爱因斯坦凝聚体的平均场动力学的分岔与原始多体系统的量子相变有关。作为一个例子，我们研究二维光学晶格中的带内隧穿。这样的系统便于通过晶格深度进行控制，也便于对相变进行宏观可视化。该系统在两个自陷态之间切换，或者从一个自陷态切换到宏观占据的自陷态的叠加态，控制参数在分岔点附近呈阶梯状变化。我们还观察到微观上偶数和奇数原子数之间的差异放大为系统宏观上可区分的动力学。
