Correlated electrons in moiré materials - from unconventional superconductivity to the chiral phase transition

Correlated quantum materials display a variety of fascinating and potentially useful phases of matter, which are based on many-body effects in a quantum regime. In the last years, moiré materials have emerged as a promising platform to study these many-body effects. Moiré materials are made from combining 2D materials via stacking or twisting. They can be manipulated comparatively easily via voltage knobs and external fields. This leads to an extreme versatility and tunabilty, which allows us to investigate a broad range of emergent quantum states. We focus on two examples in the talk: unconventional superconductivity in twisted WSe2 and the chiral phase transition in twisted bilayer graphene. In both cases, the interaction strength can be tuned via a twist angle and strongly affects the ground states. We determine where superconductivity from an electronic pairing mechanism can occur in the phase diagram of twisted WSe2 when the interaction strength and an external displacement field are varied. In twisted bilayer graphene, we demonstrate that it realises the sought-after quantum critical point of a relativistic semimetal-to-insulator transition with fermionic critical behavior described by the Gross Neveu model.