论文标题
耦合量子点腔体系统的半古典建模：从偏光顿的动力学到拉比振荡
Semiclassical modeling of coupled quantum dot-cavity systems: From polariton-like dynamics to Rabi oscillations
论文作者
论文摘要
光子腔中的半导体量子点是强烈耦合的光物质系统，并在光电设备和量子信息处理中具有前瞻性应用。在这里，我们介绍了平面量子点集合的耦合激子 - 光场动力学的理论研究，该集合被视为两级系统，嵌入了由麦克斯韦方程模拟的光子腔中。当通过将外部短激光脉冲耦合到空腔中时，我们发现激发弱的激发和狂犬振荡行为具有强烈的激发，并在这些方案之间急剧过渡。在过渡区域中，我们发现高度非线性动力学涉及基本振荡的高谐波。 We perform a numerical study based on the Finite-Difference-Time-Domain method for the solution of Maxwell's equations coupled to Bloch equations for the quantum dots and also derive an analytical model to describe the coupled cavity-quantum dot system, which allows us to describe the light field dynamics in terms of a Newton-like dynamics in an effective anharmonic potential.从这种电势的形状与初始条件相结合，可以很好地理解过渡。然后将模型扩展到宽阔的量子点集合。对于弱激发，极性光谱扩大，线略有变化，但是，仍然存在向拉比振荡制度的急剧过渡。此外，我们发现了第二个，较低的阈值，并在光谱中带有其他线条，可以追溯到北极星模式驱动的Rabi振荡。我们的方法为光子结构中的量子点和光场的动力学提供了新的见解。
Semiconductor quantum dots in photonic cavities are strongly coupled light-matter systems with prospective applications in optoelectronic devices and quantum information processing. Here we present a theoretical study of the coupled exciton--light field dynamics of a planar quantum dot ensemble, treated as two-level systems, embedded in a photonic cavity modeled by Maxwell's equations. When excited by coupling an external short laser pulse into the cavity, we find an exciton-polariton-like behavior for weak excitation and Rabi oscillations for strong excitation with a sharp transition between these regimes. In the transition region we find highly non-linear dynamics involving high harmonics of the fundamental oscillation. We perform a numerical study based on the Finite-Difference-Time-Domain method for the solution of Maxwell's equations coupled to Bloch equations for the quantum dots and also derive an analytical model to describe the coupled cavity-quantum dot system, which allows us to describe the light field dynamics in terms of a Newton-like dynamics in an effective anharmonic potential. From the shape of this potential combined with the initial conditions the transition can be well understood. The model is then extended to a broadened ensemble of quantum dots. For weak excitation the polariton spectrum broadens and the lines slightly shift, however, the sharp transition to the Rabi oscillation regime is still present. Furthermore, we find a second, lower threshold with additional lines in the spectra which can be traced back to Rabi oscillations driven by the polariton modes. Our approach provides new insights in the dynamics of both quantum dot and light field in the photonic structure.
