Ultrafast dynamics of nonequilibrium electrons in a gold nanoparticle system
Ultrafast dynamics of nonequilibrium electrons in a gold nanoparticle system
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DOI：
10.1103/physrevb.57.11334
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发表时间：
1998-05-01
影响因子：
3.7
通讯作者：
Hirao, K
中科院分区：
文献类型：
--
作者：
Inouye, H;Tanaka, K;Hirao, K
采用飞秒泵浦探针法测量了金纳米粒子系统的瞬态吸收光谱，研究了系统的非线性响应。利用Mie散射理论拟合瞬态吸收光谱，得到了电子温度和有效阻尼常数的随时间变化。在超快区，非线性响应主要来源于被入射泵浦脉冲加热的热电子系统。值得注意的是，晶格温度通过有效阻尼常数的变化在非线性响应的第一步起着重要的作用。在超过10ps的长时间尺度区域，电子温度和晶格温度对非线性响应的贡献相当大。利用表面散射和e-p散射过程讨论了有效阻尼常数的来源。
Transient absorption spectra were measured to investigate the nonlinear response of a gold nanoparticle system by the femtosecond pump-probe method. We obtained temporal changes of electron temperatures and effective damping constants by fitting transient absorption spectra with Mie scattering theory. In the ultrafast region, the nonlinear response originates mainly from the hot electron system which is heated by the incident pump pulse. It is noteworthy that the lattice temperature plays an important role even in the first step of the nonlinear response through the change of the effective damping constant. In the long-time-scale region, over 10 ps, both the electron and the lattice temperatures contribute to the nonlinear response comparably. The origin of the effective damping constant is also discussed with the surface scattering and the e-pscattering processes.