在强交变电场驱动下双量子点分子中激子的动态行为

Dynamic Behaviors of an Exciton Confined in Coupled Quantum Dots Driven by High AC Electric Field

利用有效的两点Hubbard模型,研究了在高强度交变电场驱动下的双量子点分子中激子的动力学行为。利用微扰理论,求解Floquet方程,从而得到准能的解析解,表明准能随交变电场的变化出现一系列共振点。通过计算初始局域态随时间的演化,发现在这些共振点处,动态局域化能够建立起来,说明尽管驱动电场倾向于使电子和空穴在空间分离,但在合适的强外电场驱动与弱的量子点间的耦合作用下,初始局域态依旧可保持动态局域化.

With an effective two-site Hubbard model, the dynamic behaviors of an exciton confined in coupled double quantum dot system driven by high AC field are investigated. Solving the Floquet equation by the perpeturbation theory, we obtain the analytical solution of quasi-energies. The calculation shows that the quasi-energy levels versus the amplitude of external field can develop into a series of resonance point. Calculating the time evolution of the initial states, we find the initial localized state can hold on forever at the resonance point. This demonstrates that it is possible to control the entangled states on extremely short timescales using the appropriate AC field with the adjustable amplitude and frequency, which may be useful for quantum information processing.