Superconductivity in Twisted Double Bilayer Graphene Stabilized by WSe₂

Twisted double bilayer graphene (TDBG) provides a fascinating platform to study correlated electron physics, where the bandwidth and band topology can be tuned by gate voltages. Although correlated insulating states, anomalous hall effect, and signatures of non-trivial band topology have been realized, superconductivity has not, despite its appearance in other graphene-based van der Waals heterostructures. Here, we report on the observation of superconductivity in TDBG proximitized with semiconducting WSe₂, based on two WSe₂/TDBG samples with twist angles of 1.24 and 1.37 degrees. Superconductivity emerged in the first moiré valence band for the 1.24 degree sample, and in the conduction band for the 1.37 degree sample, both with a small critical temperature of ~100 mK. Superconductivity was confirmed by non-linear current-voltage characteristics, and suppression of critical current with perpendicular magnetic field showing phase coherent Fraunhofer-like patterns. In both cases, low-field Hall measurements reveal that superconductivity emerges from a spin-valley degenerate metal, but close to a van Hove singularity and adjacent to a region susceptible to interaction-induced spin polarization. These results highlight the correlation between a high density of states and the emergence of superconductivity in TDBG while indicating a possible role for spin fluctuations in the pairing.