论文标题
平面费米子模型中的超导相变
Superconducting phase transition in planar fermionic models with Dirac cone tilting
论文作者
论文摘要
在具有四个弗米昂相互作用的平面效率模型的背景下，研究了手性和超导差距。显示并讨论了狄拉克锥体倾斜度对两个差距的影响。我们的结果指出了平面费米奇系统表现出的两种不同的行为。我们表明，有效倾斜参数有一个阈值$ \ tilde {t}^*$，因此当$ | {\ bf \ tilde {t}} | <\ tilde {t}^*$，超导耦合常数负值的超导相位。对于超导耦合常数的正值，存在化学电位的超导间隙的诱导，并且与石墨烯样系统中看到的相似。对于$ | {\ bf \ tilde {t}} | > \ tilde {t}^*$和一个负超导耦合常数，可以存在超导阶段，但仅限于相肖像中的较小区域。我们的分析还表明，当$ | {\ bf \ tilde {t}} | > \ tilde {t}^*$，对于超导耦合常数的正值，排除了化学势存在下超导间隙的诱导。在这种情况下，化学势的增加有利于金属阶段的表现。
The chiral and superconducting gaps are studied in the context of a planar fermion model with four-fermion interactions. The effect of the tilt of the Dirac cone on both gaps is shown and discussed. Our results point to two different behaviors exhibited by planar fermionic systems. We show that there is a threshold value $\tilde{t}^*$ for the effective tilt parameter such that when $|{\bf \tilde{t}}| < \tilde{t}^*$, the superconducting phase persists for negative values of the superconducting coupling constant. For positive values of the superconducting coupling constant, the induction of a superconducting gap by a chemical potential exists and which is similar to the one seen in graphene-like systems. For $|{\bf \tilde{t}}| > \tilde{t}^*$ and a negative superconducting coupling constant, the superconducting phase can be present, but it is restricted to a smaller area in the phase portrait. Our analysis also shows that when $|{\bf \tilde{t}}| > \tilde{t}^*$ and for positive values for the superconducting coupling constant, the induction of a superconducting gap in the presence of a chemical potential is ruled out. In this case, the increase of the chemical potential works in favor of the manifestation of a metallic phase.
