二能级体系的动态局域化

综述了我们在二能级体系的动态局域化方面所作的工作.通过把受驱二能级体系的量子动力学映射到在二维谐性势场和与之垂直的周期性磁场中粒子的经典动力学,使得对局域化机制理解更为深刻.应用这种方案就可以得到在线性偏振场作用下二能级体系的局域化条件.同时解析地分析了在脉冲场和圆偏振场驱动下二能级体系的局域化,发现圆偏振场诱导的局域化可以由复平面上单位圆中的椭圆完全刻画.

Dynamical Localization of Two-level Systems

This paper reviews our work on dynamical localization of the two-level system (TLS). By mapping the quantum dynamics of a driven TLS to the classical one of a particle experiencing a two-dimensional harmonic force as well as a periodic magnetic field, deep insights into the mechanism of localization have been gained. Using this scheme we are able to obtain the condition for localization of a TLS subject to the linearly polarized field. The localization induced by δ-function pulses and circularly polarized fields has been analytically investigated. It is found that the circularly-polarized-field induced localization can be fully described by the geometry of an ellipse within a unit circle on a complex plane.