论文标题
quasi-two-two二维分子导体$α$ - （下注）$ _ 2 $ i $ _3 $的环境压力狄拉克电子系统
Ambient pressure Dirac electron system in quasi-two-dimensional molecular conductor $α$-(BETS)$_2$I$_3$
论文作者
论文摘要
我们在准周围的分子导体$α$ - （下注）$ _ 2 $ i $ _3 $下在环境压力下研究了精确的晶体结构和电子状态。 The electronic resistivity of this molecular solid shows metal-to-insulator (MI) crossover at $T_{MI}$=50 K. Our x-ray diffraction and $^{13}$C nuclear magnetic resonance experiments revealed that $α$-(BETS)$_2$I$_3$ maintains the inversion symmetry below $T_{MI}$.第一原理的计算发现一对一般的K-Point，而脱名的接触点处于费米水平。该系统中绝缘状态的起源是旋转轨道相互作用打开的〜2 meV的小能量差距。 Z $ _2 $拓扑不变性表明该系统是弱拓扑绝缘子。我们的结果表明，$α$ - （BETS）$ _ 2 $ i $ _3 $是一种有前途的材料，用于在二维中研究散装狄拉克电子系统。
We investigated the precise crystal structures and electronic states in a quasi-two-dimensional molecular conductor $α$-(BETS)$_2$I$_3$ at ambient pressure. The electronic resistivity of this molecular solid shows metal-to-insulator (MI) crossover at $T_{MI}$=50 K. Our x-ray diffraction and $^{13}$C nuclear magnetic resonance experiments revealed that $α$-(BETS)$_2$I$_3$ maintains the inversion symmetry below $T_{MI}$. First-principles calculations found a pair of anisotropic Dirac cones at a general k-point, with the degenerate contact points at the Fermi level. The origin of the insulating state in this system is a small energy gap of ~2 meV opened by the spin-orbit interaction. The Z$_2$ topological invariants indicate that this system is a weak topological insulator. Our results suggest that $α$-(BETS)$_2$I$_3$ is a promising material for studying the bulk Dirac electron system in two dimensions.
