Time-dependent density functional theory for strong electromagnetic fields in crystalline solids
Time-dependent density functional theory for strong electromagnetic fields in crystalline solids
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DOI：
10.1103/physrevb.85.045134
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发表时间：
2011-12
影响因子：
3.7
通讯作者：
K. Yabana;T. Sugiyama;Y. Shinohara;T. Otobe;G. Bertsch
中科院分区：
文献类型：
--
作者：
K. Yabana;T. Sugiyama;Y. Shinohara;T. Otobe;G. Bertsch
本文应用含时密度泛函理论和麦克斯韦方程组的耦合动力学方法研究了强激光脉冲与晶体硅的相互作用。作为电磁场强度的函数，我们在响应中看到几个区域。在最低强度下，脉冲的反射和透射符合介电响应的雅阁，能量沉积的特征符合双光子吸收。吸收过程开始偏离激光强度约为10^13 W/cm ^2时的吸收过程，此时沉积的能量约为每个原子1 eV。反射率的变化被视为强度的函数。当它通过约3 × 1012 W/cm 2的阈值时，有一个小的下降。在较高的强度下，高于2 × 10^13 W/cm ^2，反射率强烈增加。这种行为可以定性地理解在一个模型中处理的激发电子空穴对作为等离子体。
We apply the coupled dynamics of time-dependent density functional theory and Maxwell equations to the interaction of intense laser pulses with crystalline silicon. As a function of electromagnetic field intensity, we see several regions in the response. At the lowest intensities, the pulse is reflected and transmitted in accord with the dielectric response, and the characteristics of the energy deposition is consistent with two-photon absorption. The absorption process begins to deviate from that at laser intensities ~ 10^13 W/cm^2, where the energy deposited is of the order of 1 eV per atom. Changes in the reflectivity are seen as a function of intensity. When it passes a threshold of about 3 \times 1012 W/cm2, there is a small decrease. At higher intensities, above 2 \times 10^13 W/cm^2, the reflectivity increases strongly. This behavior can be understood qualitatively in a model treating the excited electron-hole pairs as a plasma.