Long-Range Propagation and Interference of $d$-wave Superconducting Pairs in Graphene

Recent experiments have shown that proximity with high-temperature superconductors induces unconventional superconducting correlations in graphene. Here we demonstrate that those correlations propagate hundreds of nanometer, allowing for the unique observation of $d$-wave Andreev pair interferences in YBa${}_2$Cu${}_3$O${}_7$-graphene devices that behave as a Fabry-P'erot cavity. The interferences show as a series of pronounced conductance oscillations analogous to those originally predicted by de Gennes–Saint-James for conventional metal-superconductor junctions. The present work is pivotal to the study of exotic directional effects expected for nodal superconductivity in Dirac materials.