论文标题
二次带触摸系统的重新归一化组研究
Renormalization group study of systems with quadratic band touching
论文作者
论文摘要
在此，由于化学电位变化，在两个二次带接触点的两个2D系统中的LIFSHITZ过渡已在此处进行。相互作用的效果已经使用了重新归一化组（RG）研究，发现在过渡时，排斥相互作用略有相关，并且有吸引力的相互作用在略有无关。我们通过研究可准确获得基态和绿色功能的微观模型来证实从RG计算获得的结果。我们发现，从过渡中，系统表现出对形成和激子冷凝物的不稳定性。
Lifshitz transitions in two 2D systems with a single quadratic band touching point as the chemical potential is varied have been studied here. The effects of interactions have been studied using the renormalization group (RG) and it is found that at the transition a repulsive interaction is marginally relevant and an attractive interaction is marginally irrelevant. We corroborate the results obtained from the RG calculation by studying a microscopic model whose ground state and Green's functions can be obtained exactly. We find that away from the transition, the system displays an instability towards forming and excitonic condensate.
