Microscopic analysis of relaxation mechanisms from energy- and time-resolved two-photon photoemission spectra of metal surfaces
Microscopic analysis of relaxation mechanisms from energy- and time-resolved two-photon photoemission spectra of metal surfaces
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从金属表面的能量和时间分辨双光子光电发射光谱对弛豫机制进行微观分析
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发表时间：
2005
期刊：
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通讯作者：
M. Sakaue
中科院分区：
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作者：
M. Sakaue
从电子系统的多体动力学观点出发，提出了金属表面能量和时间分辨(ER-和TR-)双光子光电发射的微观理论。用非平衡格林函数方法研究了空穴动力学对表面占位态的影响。在基于密度矩阵方法的宏观理论中，通常认为退相是由弹性散射引起的，能量弛豫是由非弹性散射引起的，然而，从占据态到体相的光激发空穴的非弹性电子-电子散射可以解释能量弛豫的退相和加速。在对铜(111)面上的ER-和TR-2PPE进行解析和数值分析的基础上，阐明了宏观弛豫时间与电子寿命和空穴寿命的关系。
Microscopic theory of energy- and time-resolved (ER- and TR-) two-photon photoemission (2PPE) from metal surfaces is presented from the viewpoint of many-body dynamics of the electron system. The effects of hole dynamics in the occupied states at the surfaces are investigated by the nonequilibrium Green function method. In the macroscopic theory based on the density matrix method, it is usually considered that dephasing is due to elastic scattering and energy relaxation is due to inelastic scattering; however, it is demonstrated that inelastic electron–electron scattering of the photoexcited holes from the occupied states to the bulk can account for both dephasing and acceleration of energy relaxation. On the basis of analytical and numerical analyses for ER- and TR-2PPE on Cu(111), the relations of the macroscopic relaxation times with the electron and hole lifetimes are clarified.