Graphene-based, high-quality, two-dimensional electronic systems have emerged as a highly tunable platform for studying superconductivity^{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21}. Specifically, superconductivity has been observed in both electron- and hole-doped twisted graphene moiré systems^{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17}, whereas in crystalline graphene systems, superconductivity has so far been observed only in hole-doped rhombohedral trilayer graphene (RTG)¹⁸ and hole-doped Bernal bilayer graphene (BBG)^19,20,21. Recently, enhanced superconductivity has been demonstrated^20,21 in BBG because of the proximity to a monolayer WSe₂. Here we report the observation of superconductivity and a series of flavour-symmetry-breaking phases in electron- and hole-doped BBG/WSe₂ devices by electrostatic doping. The strength of the observed superconductivity is tunable by applied vertical electric fields. The maximum Berezinskii–Kosterlitz−Thouless transition temperature for the electron- and hole-doped superconductivity is about 210 mK and 400 mK, respectively. Superconductivities emerge only when the applied electric fields drive the BBG electron or hole wavefunctions towards the WSe₂ layer, underscoring the importance of the WSe₂ layer in the observed superconductivity. The hole-doped superconductivity violates the Pauli paramagnetic limit, consistent with an Ising-like superconductor. By contrast, the electron-doped superconductivity obeys the Pauli limit, although the proximity-induced Ising spin–orbit coupling is also notable in the conduction band. Our findings highlight the rich physics associated with the conduction band in BBG, paving the way for further studies into the superconducting mechanisms of crystalline graphene and the development of superconductor devices based on BBG.

基于石墨烯的高质量二维电子系统已成为研究超导性的高度可调平台^{1,2,3,4,5,6,7,8,9,10,11,12,13,14 ,15,16,17,18,19,20,21} .具体来说，在电子和空穴掺杂的扭曲石墨烯云纹系统中都观察到了超导性^{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,}如图¹⁷所示，而在结晶石墨烯系统中，迄今为止仅在空穴掺杂菱形三层石墨烯(RTG) ¹⁸和空穴掺杂伯纳尔双层石墨烯(BBG) ^19,20,21中观察到超导性。最近，由于 BBG 接近单层 WSe ₂ ，增强的超导性已被证明^20,21 。在这里，我们报告了通过静电掺杂在电子和空穴掺杂 BBG/WSe ₂器件中观察到的超导性和一系列风味对称性破缺相。观察到的超导性的强度可以通过施加垂直电场来调节。电子和空穴掺杂超导的最大 Berezinskii-Kosterlitz-Thouless 转变温度分别约为 210 mK 和 400 mK。仅当施加的电场将 BBG 电子或空穴波函数驱动至 WSe ₂层时，才会出现超导性，这强调了 WSe ₂层在观察到的超导性中的重要性。空穴掺杂超导违反了泡利顺磁极限，与类伊辛超导体一致。相比之下，电子掺杂超导遵循泡利极限，尽管邻近引起的伊辛自旋轨道耦合在导带中也很明显。 我们的研究结果强调了与 BBG 导带相关的丰富物理特性，为进一步研究晶体石墨烯的超导机制和基于 BBG 的超导器件的开发铺平了道路。