论文标题
在压力下
Quantum Phase Transition in Organic Massless Dirac Fermion System $α $-(BEDT-TTF)$_2$I$_3$ under pressure
论文作者
论文摘要
我们调查了强电子相关性对无质量的狄拉克费米恩系统的影响，$α$ - （bedt-ttf）$ _ 2 $ i $ _3 $，在压力下。在这种有机盐中，人们可以通过改变压力并访问无质量的狄拉克费米阶段和电荷排序阶段之间的量子临界点来控制电子相关。从理论上讲，我们通过应用奴隶旋转理论来研究该系统的电子结构，并发现费米的速度降低而不会在接近无质量的dirac fermion阶段接近量子临界点时产生质量间隙。我们表明，费米速度的压力依赖性与实验的结果有很好的定量一致，在该实验的结果中，通过分析掺杂样品中的shubnikov-de haas振荡来确定费米速度。我们的结果表明，即使在存在强电子相关性的情况下，无质量的狄拉克费物系统也会表现出量子相变的而没有产生质量间隙。
We investigate the effect of strong electronic correlation on the massless Dirac fermion system, $α$-(BEDT-TTF)$_2$I$_3$, under pressure. In this organic salt, one can control the electronic correlation by changing pressure and access the quantum critical point between the massless Dirac fermion phase and the charge ordering phase. We theoretically study the electronic structure of this system by applying the slave-rotor theory and find that the Fermi velocity decreases without creating a mass gap upon approaching the quantum critical point from the massless Dirac fermion phase. We show that the pressure-dependence of the Fermi velocity is in good quantitative agreement with the results of the experiment where the Fermi velocity is determined by the analysis of the Shubnikov-de Haas oscillations in the doped samples. Our result implies that the massless Dirac fermion system exhibits a quantum phase transition without creating a mass gap even in the presence of strong electronic correlations.
