Anomalous Intrinsic Superconducting Diode Effect in Rhombohedral Graphene

Recently, major advances in the field of superconductivity directed at the observation of non-reciprocal supercurrent under very peculiar circumstances. This so-called superconducting diode effect (SDE) gained increasing interest due to promising applications. So far, the SDE could be realized by special device geometries like well-designed Josephson junctions or by applying an external magnetic field in superconducting materials with strong spin-orbit couplings (SOC). In this talk, we will discuss our theoretical investigation of a new type of intrinsic SDE that appears anomalously in homogeneous rhombohedral multilayer graphene in the absence of both SOC and magnetic field [1]. We will show the required symmetry breaking is a consequence of the interplay between Stoner magnetism, quarter-metal superconductivity, and band warping [1].

[1] C. Yoon, T. Xu, Y. Barlas, and F. Zhang, arXiv: 2502.17555 (2025)