论文标题
来自魔术角石墨烯中瓦尔利金石模式的旋转三个超导性
Spin-triplet superconductivity from inter-valley Goldstone modes in magic-angle graphene
论文作者
论文摘要
我们考虑围绕电荷中立性的兴奋剂方向上的魔法石墨烯，并研究了零掺杂的最近提出的 - 瓦利相干绝缘子与相邻的超导圆顶之间的联系。魔术角石墨烯连续模型具有新兴的U（1）山谷 - 电荷保护对称性，而出现的SU（2）对称对应于两个山谷中的相反自旋旋转。瓦利间的连贯的绝缘子自发地打破了这两个新出现的对称性，因此具有四个戈德石模式，它们夫妇掺入了电荷载体。我们得出了由金石模式介导的有效相互作用，并研究了其在电子对形成中的作用。 SU（2）Goldstone模式产生了铁磁相互作用，该相互作用在自旋三型配对通道中具有吸引力，并在自旋单向通道中排斥。从弱耦合BCS计算中，我们发现了P-WAVE通道中的主要超导不稳定。
We consider magic-angle graphene in the doping regime around charge neutrality and study the connection between a recently proposed inter-valley coherent insulator at zero doping and the neighboring superconducting domes. The magic-angle graphene continuum model has an emergent U(1) valley-charge conservation symmetry, and an emergent SU(2) symmetry corresponding to opposite spin rotations in the two valleys. The inter-valley coherent insulator spontaneously breaks both these emergent symmetries, and as a result has four Goldstone modes which couple to doped charge carriers. We derive the effective interaction mediated by the Goldstone modes, and study its role in electron pair formation. The SU(2) Goldstone modes generate a ferromagnetic interaction, which is attractive in spin-triplet pairing channels and repulsive in spin-singlet channels. From a weak-coupling BCS calculation, we find the leading superconducting instability in the p-wave channel.
