First-principles study of ultrafast and nonlinear optical properties of graphite thin films
First-principles study of ultrafast and nonlinear optical properties of graphite thin films
复制标题
DOI：
10.1103/physrevb.103.085433
复制
发表时间：
2020-09
期刊：
影响因子：
--
通讯作者：
M. Uemoto;Shintaro Kurata;Norihito Kawaguchi;K. Yabana
中科院分区：
文献类型：
--
作者：
M. Uemoto;Shintaro Kurata;Norihito Kawaguchi;K. Yabana
本文基于第一性原理含时密度泛函理论，研究了石墨薄膜的超快非线性光学性质。我们首先计算了强脉冲电场作用下石墨单胞中的电子动力学，并探讨了石墨的瞬态光学性质。结果表明，在一定的外加电场强度范围内，石墨的光学响应呈现出从导电相到绝缘相的突变。它也表现为可饱和吸收，即从电场到电子的能量转移的饱和。接下来，我们通过同时求解电子和电磁场的耦合动力学来研究光在石墨薄膜中的传播。观察到可饱和吸收表现为在电场幅度约为4 × 7 × 10 - 2 V/埃的空间区域中具有小衰减的传播。
We theoretically investigate ultrafast and nonlinear optical properties of graphite thin films based on first-principles time-dependent density functional theory. We first calculate electron dynamics in a unit cell of graphite under a strong pulsed electric field and explore the transient optical properties of graphite. It is shown that the optical response of graphite shows a sudden change from conducting to insulating phase at a certain intensity range of the applied electric field. It also appears as a saturable absorption, the saturation in the energy transfer from the electric field to electrons. We next investigate a light propagation in graphite thin films by solving coupled dynamics of the electrons and the electromagnetic fields simultaneously. It is observed that the saturable absorption manifests in the propagation with small attenuation in the spatial region where the electric field amplitude is about $4 \sim 7 \times 10^{-2}$ V/Angstrom.