Calculation of low-energy-electron lifetimes
Calculation of low-energy-electron lifetimes
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低能电子寿命的计算
DOI：
10.1103/physrevb.60.2326
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发表时间：
1999
影响因子：
3.7
通讯作者：
P. Echenique
中科院分区：
文献类型：
--
作者：
E. Zarate;P. Apell;P. Echenique
用黄金法则的方法研究了态密度对金属中低能电子寿命的影响。对金属的实际态密度进行了简单的近似分析，结果表明寿命的自由电子标度$(E\ensuremath{-}{E}_{F}{)}^{\ensuremath{-}2}$在$d$电子贡献开始时受到影响。因此，在贵金属中，一个标度为$(E\ensuremath{-}{E}_{F}\ensuremath{-}{\ensuremath{\omega}}_{d}{)}^{\ensuremath{-}2}的标度，其中${\ensuremath{\omega}}_{d}$是费米能到$d$能带顶部的能量距离，一旦$d$电子可以被激发就会出现。在铁磁性Co中，多数自旋电子和少数自旋电子的寿命之比在多数自旋电子激发阈值以下与能量无关，而该比值随着能量高于该点而增加。
The effect of the density of states on the lifetime of low-energy electrons in metals has been studied using a golden rule approach. Simple approximations to the real density of states of metals have been used allowing analytical results, which show that the free-electron scaling $(E\ensuremath{-}{E}_{F}{)}^{\ensuremath{-}2}$ of the lifetime is affected above the onset of $d$-electron contributions. Hence, in noble metals a scaling with $(E\ensuremath{-}{E}_{F}\ensuremath{-}{\ensuremath{\omega}}_{d}{)}^{\ensuremath{-}2},$ where ${\ensuremath{\omega}}_{d}$ is the energy distance from the Fermi energy to the top of the $d$ band, appears once $d$ electrons can be excited. In ferromagnetic Co, the ratio between the lifetimes of majority and minority spin electrons is found energy independent below the threshold for the excitation of majority $d$ electrons while this ratio increases with energy above that point.