论文标题
Attosend瞬时吸收光谱的对称特性在晶介质中
Symmetry properties of attosecond transient absorption spectroscopy in crystalline dielectrics
论文作者
论文摘要
我们从理论上研究了晶体对称性与使用强度泵和attosecond探针场中晶体介电的光学特性的晶体对称性和瞬态调制之间的关系。当泵场的光子能远低于带隙能，光电导率的调节是由图内电子运动引起的，即动态的Franz-keldysh效应。我们分析利用休斯顿函数的调制光导率的对称特性，并得出一个将吸收时时间振荡与调制光学电导率的转化特性相关的公式。为了验证公式的有效性，我们基于时间依赖性密度功能理论进行实时第一原理计算，以将4H-SIC晶体作为一个例子。
We theoretically investigate a relation between the crystalline symmetry and the transient modulation of optical properties of crystalline dielectrics in pump-probe measurements using intense pump and attosecond probe fields. When the photon energy of the pump field is much below the bandgap energy, the modulation of the optical conductivity is caused by the intraband electronic motion, that is, the dynamical Franz-Keldysh effect. We analytically investigate symmetry properties of the modulated optical conductivity utilizing the Houston function, and derive a formula that relates the temporal oscillation in the absorption with the transformation properties of the modulated optical conductivity. To verify the validity of the formula, we perform real-time first-principles calculations based on the time-dependent density functional theory for a pump-probe process taking 4H-SiC crystal as an example.
