Reentrant Superconductivity in Strong Magnetic Field: The Case for Moir{\'e} Superconductors*

Based on the experimental Landau fan and Shubnikov-de Haas data of twisted bilayer graphene (tBG) and twisted double bilayer graphene (tDBG), we study a simple continuum model under perpendicular magnetic field and short range attractive electron-electron interactions. We show that the moir{\'e} based superconductors are ideal platform to observe reentrant superconductivity in Landau level regime; a phase long proposed but never observed experimentally. We first generalize the theory of reentrant superconductivity to a multiband case and include the effect of Landau level broadening due to disorder and periodic potential, which best represents the experimental data and then show that the parameter range in tBG and tDBG is ideal to observe reentrant superconductivity. We further comment on experimental implications and other possible systems for this phase.