Symmetric and Tunable Superconductivity in WSe₂-Encapsulated Bernal Bilayer Graphene

High-quality crystalline graphene integrated with transition metal dichalcogenide (TMD) substrates provides a versatile platform to investigate the relationship between spin–orbit coupling (SOC) and superconductivity. In Bernal bilayer graphene (BBG) proximitized by a TMD, virtual tunneling processes induce a layer-selective SOC in graphene, thereby stabilizing superconductivity in the layer whose electronic wavefunction couples more strongly to the TMD. In a double-encapsulated heterostructure (WSe₂–BBG–WSe₂), we observe a nearly symmetric superconducting phase diagram spanning both electron- and hole-doped regimes, with variations arising from the distinct SOC strengths induced in the top and bottom graphene layers. These findings demonstrate that SOC not only enhances superconductivity in BBG but also serves as a powerful tuning parameter for engineering superconducting states in van der Waals heterostructures.