Chou Yang-Zhi, Wu Fengcheng, Sau Jay D, Das Sarma Sankar
Condensed Matter Theory Center and Joint Quantum Institute, Department of Physics, University of Maryland, College Park, Maryland 20742, USA.
School of Physics and Technology, Wuhan University, Wuhan 430072, China.
Phys Rev Lett. 2021 Oct 29;127(18):187001. doi: 10.1103/PhysRevLett.127.187001.
Motivated by the observation of two distinct superconducting phases in the moiréless ABC-stacked rhombohedral trilayer graphene, we investigate the electron-acoustic-phonon coupling as a possible pairing mechanism. We predict the existence of superconductivity with the highest T_{c}∼3 K near the Van Hove singularity. Away from the Van Hove singularity, T_{c} remains finite in a wide range of doping. In our model, the s-wave spin-singlet and f-wave spin-triplet pairings yield the same T_{c}, while other pairing states have negligible T_{c}. Our theory provides a simple explanation for the two distinct superconducting phases in the experiment and suggests that superconductivity and other interaction-driven phases (e.g., ferromagnetism) can have different origins.
受无莫尔 ABC 堆叠菱面体三层石墨烯中两个不同超导相的观测结果启发，我们研究了电子 - 声子耦合作为一种可能的配对机制。我们预测在范霍夫奇点附近存在最高临界温度(T_{c}\sim3 K)的超导性。远离范霍夫奇点时，在很宽的掺杂范围内(T_{c})仍然有限。在我们的模型中，s 波自旋单重态和 f 波自旋三重态配对产生相同的(T_{c})，而其他配对态的(T_{c})可忽略不计。我们的理论为实验中的两个不同超导相提供了一个简单解释，并表明超导性和其他相互作用驱动的相（例如铁磁性）可能有不同的起源。
