Anisotropic superconducting transport in rhombohedral hexalayer graphene

Superconductors with unconventional order parameters are often intertwined with other broken-symmetry electronic phases. Here, we investigate an unconventional superconducting phase emerging in rhombohedral hexalayer graphene. Through angle-resolved transport measurements, we demonstrate an extreme anisotropy in the superconducting transport, which resembles the observed response in the surrounding metallic phase. By examining the temperature and out-of-plane magnetic-field dependence of the transport response, we identify striking hysteretic transitions upon thermal cycling and magnetic-field sweeps, which reveals the first-order melting associated with translational symmetry breaking, and the first-order valley polarization transition associated with an orbital ferromagnet. Together, these findings reveal a superconducting state intertwined with the stripe order and orbital magnetism, in which rotational, translational, and time-reversal symmetries are simultaneously broken in rhombohedral hexalayer graphene.