Enhanced Superconductivity in Spin-Orbit Proximitized Bernal Bilayer Graphene

In the presence of a large electric field, Bernal bilayer graphene (BLG) features several broken-symmetry phases and magnetic-field-induced superconductivity with a critical temperature T≈ 30 mK. Here, we show that placing monolayer tungsten diselenide (WSe₂) on BLG promotes Cooper pairing in several ways: superconductivity appears at zero magnetic field, exhibits an order of magnitude enhancement in Tc, and occurs over a wide density range. By mapping quantum oscillations, we establish that superconductivity emerges from a polarized normal state, with two out of four spin-valley flavors predominantly populated. For BLG-WSe₂ with moderate Ising spin-orbit coupling, in-plane magnetic field measurements reveal that the critical field roughly obeys the Pauli limit on one end of the superconducting dome yet sharply violates on the other. Moreover, the superconductivity arises only for electric fields that push BLG hole wavefunctions towards WSe₂—suggesting that proximity-induced Ising spin-orbit coupling plays a key role in stabilizing the pairing. These results provide an essential step towards engineering robust, highly tunable, and ultra-clean graphene-based superconductors.