Mesple Florie, Missaoui Ahmed, Cea Tommaso, Huder Loic, Guinea Francisco, Trambly de Laissardière Guy, Chapelier Claude, Renard Vincent T
Université Grenoble Alpes, CEA, Grenoble INP, IRIG, PHELIQS, 38000 Grenoble, France.
Laboratoire de Physique Théorique et Modélisation (UMR 8089), CY Cergy Paris Université, CNRS, 95302 Cergy-Pontoise, France.
Phys Rev Lett. 2021 Sep 17;127(12):126405. doi: 10.1103/PhysRevLett.127.126405.
The moiré of twisted graphene bilayers can generate flat bands in which charge carriers do not possess enough kinetic energy to escape Coulomb interactions with each other, leading to the formation of novel strongly correlated electronic states. This exceptionally rich physics relies on the precise arrangement between the layers. Here, we survey published scanning tunneling microscope measurements to prove that near the magic-angle, native heterostrain, the relative deformations between the layers, dominates twist in determining the flat bands as opposed to the common belief. This is demonstrated at full filling where electronic correlations have a weak effect and where we also show that tip-induced strain can have a strong influence. In the opposite situation of zero doping, we find that electronic correlation further renormalizes the flat bands in a way that strongly depends on experimental details.
扭曲双层石墨烯的莫尔条纹可以产生平带，其中电荷载流子没有足够的动能来逃脱彼此之间的库仑相互作用，从而导致形成新型的强关联电子态。这种极其丰富的物理现象依赖于各层之间的精确排列。在这里，我们审视已发表的扫描隧道显微镜测量结果，以证明在接近魔角时，原生异质应变，即层间的相对变形，在决定平带方面比扭转起主导作用，这与普遍看法相反。这在完全填充时得到了证明，此时电子关联效应较弱，我们还表明针尖诱导应变会产生强烈影响。在零掺杂的相反情况下，我们发现电子关联以一种强烈依赖于实验细节的方式进一步重整化平带。
