Much progress has been done in the controlled stacking of two-dimensional crystals, leading to (i) well-defined Moiré systems where the layers are rotated with respect to each other or (ii) simply achieving a metastable configuration within the initial unit cell. Through such advances, a plethora of new correlated phases has been observed, ranging from unconventional superconductivity, over anomalous quantum Hall ferromagnetism, to ferroelectricity.
After an overview of recent experimental findings, I will first summarize what this “magic” is all about. I will then discuss our theoretical results on the electronic phases in twisted bilayer graphene. For trilayer graphene, I will present our theory on the superconducting instability and Hall density.
Finally, I will also show preliminary results for quadrilayer graphene that may allow conclusions on the possibly universal pairing mechanism in these systems.