论文标题
$α$ -STF $ _2 $ i $ _3 $在环境温度和压力下的奇异狄拉克锥
Exotic Dirac Cones on the Band Structure of $α$-STF$_2$I$_3$ at Ambient Temperature and Pressure
论文作者
论文摘要
The quasi-two-dimensional molecular semimetallic conductor $α$-STF$_2$I$_3$ is isostructural with $α$-ET$_2$I$_3$.The latter possesses a unique band structure showing a zero-gap state with Dirac cones under high pressure, whereas the band structure of the former has been elusive because of heavy disorder at all the donor sites.为了阐明$α$ -STF $ _2 $ i $ _3 $的频带结构，已经提出了一种基于观察到的原子参数为296 K和1 bar的理论方法。结果表明，STF盐应具有在环境压力和温度下具有狄拉克锥体的带状结构，这应该促进对该系统的未来实验研究。使用扩展的Hückel方法，我们证明，$α$ -STF $ -STF $ _2 $ _2 $ i $ _3 $的DIRAC点与时间反向旋转动量（Trim）（TRIM）相称。这种新颖的狄拉克锥体，即传导和价带之间的能量差具有相当大的各向异性，它在修剪处的波函数的奇偶校验方面被阐明了。我们提出了当前$α$ -STF $ _2 $ i $ _3 $的电导率测量，预计将显示出大型各向异性作为当前狄拉克电子的特征。
The quasi-two-dimensional molecular semimetallic conductor $α$-STF$_2$I$_3$ is isostructural with $α$-ET$_2$I$_3$.The latter possesses a unique band structure showing a zero-gap state with Dirac cones under high pressure, whereas the band structure of the former has been elusive because of heavy disorder at all the donor sites. To elucidate the band structure of $α$-STF$_2$I$_3$, a theoretical method based on the observed atomic parameters at 296 K and 1 bar has been proposed. The results suggest that the STF salt should have a band structure with Dirac cones under ambient pressure and temperature, which should promote future experimental studies on this system.Using the extended Hückel method, we demonstrate that the Dirac points of $α$-STF$_2$I$_3$ are aligned to be symmetric with respect to a time reversal invariant momentum (TRIM). Such novel Dirac cones, where the energy difference between the conduction and valence bands has considerable anisotropy, are clarified in terms of the parity of the wavefunction at the TRIM. We propose the conductivity measurement on the present $α$-STF$_2$I$_3$, which is expected to show a large anisotropy as a characteristic of the present Dirac electrons.
