论文标题
基于第一原理计算的Al-MG-Zn准晶体的电子状态及其大约
Electronic States of Al-Mg-Zn Quasicrystal and Its Approximant based on the First-Principles Calculations
论文作者
论文摘要
进行第一原则计算以调查具有组成的1/1和2/1近似值的电子状态，其构成al $ _ {15} $ Zn $ _ {40} $ mg $ _ {45} $，靠近quasicrystal（qc）al $ _ {14.9} $ _n $ _1 $ _1 $ _1}最近发现了超导性。 1/1近似值的状态密度显示在QC的各种近似值中通常观察到的Fermi水平附近的较宽的伪模结构，而对于2/1近似值的较大的伪造结构并未显示出如此广泛的假单。与1/1近似值相比，2/1近似值在费米水平上显示出显着的狭窄伪群，而不是宽的假单，它显示出显着的狭窄伪群，该近似值显示了宽pseudoGap内的费米水平的浅驼峰。这似乎与对电阻率的实验观察一致，这随着从室温从室温降低到围绕超导转换温度的降低，对于2/1近似值，与QC一起增加，而1/1近似值的QC则单调降低。
First-principles calculations are performed to investigate the electronic states of 1/1 and 2/1 approximants with the composition Al$_{15}$Zn$_{40}$Mg$_{45}$ which is close to the quasicrystal (QC) Al$_{14.9}$Zn$_{41.0}$Mg$_{44.1}$ in which the superconductivity is recently discovered. The density of states for the 1/1 approximant shows a wide pseudogap structure near the Fermi level as commonly observed in various approximants of the QCs, whereas those for the 2/1 approximant do not show such a wide pseudogap. Instead of the wide pseudogap, the 2/1 approximant shows a remarkable narrow pseudogap at the Fermi level in contrast to the 1/1 approximant, which shows a shallow hump at the Fermi level within the wide pseudogap. This seems to be consistent with the experimental observation of the electrical resistivity, which increases with decreasing temperature from the room temperature down to around the superconducting transition temperature for the 2/1 approximant together with the QC, whereas it monotonically decreases for the 1/1 approximant.
