论文标题
使用schwinger-dyson方程在三维迪拉克半金属中的相变
Phase transitions in 3-dimensional Dirac semi-metals using Schwinger-Dyson equations
论文作者
论文摘要
我们通过求解一组Schwinger-Dyson方程来研究三维狄拉克半金属中的半金属/绝缘体量子相变。我们研究各向异性费米速度对过渡的临界耦合的影响。我们考虑了文献中常用的几种不同近似值的影响，并表明当其中一些近似值放松时，临界耦合变化的结果会发生很大变化。最重要的是，临界耦合对各向异性的依赖性的性质在很大程度上取决于用于光子极化张量的近似值。一方面，这意味着包括完整光子动力学的计算对于回答临界耦合是否随各向异性增加还是减小的基本问题是必要的。另一方面，我们的结果意味着各向异性可能会提供一种机制，以促进现实的三维狄拉克半金属材料中的动力学间隙产生。
We study the semi-metal/insulator quantum phase transition in three-dimensional Dirac semi-metals by solving a set of Schwinger-Dyson equations. We study the effect of an anisotropic fermion velocity on the critical coupling of the transition. We consider the influence of several different approximations that are commonly used in the literature and show that results for the critical coupling change considerably when some of these approximations are relaxed. Most importantly, the nature of the dependence of the critical coupling on the anisotropy depends strongly on the approximations that are used for the photon polarization tensor. On the one hand, this means that calculations that include full photon dynamics are necessary to answer even the basic question of whether the critical coupling increases or decreases with anisotropy. On the other hand, our results mean that it is possible that anisotropy could provide a mechanism to promote dynamical gap generation in realistic three-dimensional Dirac semi-metallic materials.
