Unconventional superconductivity in magic-angle twisted trilayer graphene

Magic-angle twisted trilayer graphene (MATTG) recently emerged as a highly tunable platform for studying correlated phases of matter, such as correlated insulators and superconductivity. Superconductivity occurs in a range of doping levels that is bounded by van Hove singularities, which stimulates the debate of the origin and nature of superconductivity in this material. In this work, we discuss the role of spin-fluctuations arising from atomic-scale correlations in MATTG for the superconducting state. We show that in a phase diagram as a function of doping (nu) and temperature, nematic superconducting regions are surrounded by ferromagnetic states and that a superconducting dome with T-c approximate to 2 K appears between the integer fillings nu = -2 and nu = -3. Applying a perpendicular electric field enhances superconductivity on the electron-doped side which we relate to changes in the spin-fluctuation spectrum. We show that the nematic unconventional superconductivity leads to pronounced signatures in the local density of states detectable by scanning tunneling spectroscopy measurements.

Automated summary

Magic-angle twisted trilayer graphene is a highly tunable platform for studying correlated phases of matter. In this research, we find that spin fluctuations play an important role in superconductivity, and we discover new features in the phase diagram of the superconducting state.