Two-dimensional band dispersion and momentum-resolved lifetime of image-potential state on graphite studied by angle-resolved multi-photon photoemission spectroscopy
Two-dimensional band dispersion and momentum-resolved lifetime of image-potential state on graphite studied by angle-resolved multi-photon photoemission spectroscopy
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角分辨多光子光电子能谱研究石墨上像势态的二维能带色散和动量分辨寿命
DOI：
10.1103/physrevb.85.075325
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
and Masao Kamada
中科院分区：
文献类型：
--
作者：
Kazutoshi Takahashi;Junpei Azuma;and Masao Kamada
利用角分辨多光子光电子能谱研究了高取向热解石墨表面的像势态。首次观察到具有= 1，2和3的IPS的类自由电子色散，具有高能量和动量分辨率。从谱线强度对激发密度的依赖关系以及与能量图的比较，我们认为IPS是由σ带的守恒跃迁和π带的间接跃迁构成的。本征线宽对能量的线性依赖性表明IPS带内的带内弛豫的贡献。
We studied the image-potential state (IPS) on a highly oriented pyrolitic graphite surface by means of angle-resolved multiphoton photoemission spectroscopy. The free-electron–like dispersion of IPSs with= 1, 2, and 3 is observed for the first time with high energy and momentum resolution. From the dependence of the spectral intensity on the excitation density and comparisons with the energy diagram, it is suggested that IPSs are populated by the-conserved transition from the σ-band and the indirect transition from the π-band. The linear dependence of the intrinsic line width on the energy suggests a contribution of intraband relaxation within the IPS band.