共振(粒子物理)
庚烷
化学
电导
量子隧道
分子物理学
波包
原子物理学
材料科学
物理
凝聚态物理
有机化学
作者
C. D. Lindstrom,Daniel P. Quinn,Xiaoyang Zhu
摘要
The binding energies and lifetimes of the n=1 image resonance on Au(111) are measured as a function of n-heptane layer thickness by femtosecond time-resolved two-photon photoemission (TR-2PPE) spectroscopy. The lifetime of the image resonance dramatically increases from ∼4fs on clean Au(111) to 1.6ps with three layers of n-heptane. Because the image resonance is above the L1 band edge of Au, this increase in lifetime is attributed to the tunneling barrier presented by the σ-σ* band gap of the n-heptane film. We use the one-dimensional dielectric continuum model (DCM) to approximate the surface potential and to determine the binding energies and the lifetimes of the image resonances. The exact solution of the DCM potential is determined in two ways: the first by wave-packet propagation and the second by using a tight-binding Green’s function approach. The first approach allows band-edge effects to be treated. The latter approach is particularly useful in illustrating the similarity between TR-2PPE and conductance measurements.
科研通智能强力驱动
Strongly Powered by AbleSci AI