Nonequilibrium Andreev processes in ballistic graphene Andreev interferometers

Multiterminal Josephson Junctions (JJs) have emerged as a versatile platform for exploring non-trivial current-phase relations, topological phases, and Floquet-Andreev states. In this work, we investigate the nonequilibrium Andreev processes triggered by a voltage bias in ballistic three-terminal graphene Josephson Junctions (JJs). We observe periodic resistance oscillations as a function of the voltage and magnetic field. These oscillations further exhibit a series of voltage-induced 0-π crossovers, where minima and maxima in resistance alternately occur at integer flux quanta. Our theoretical model attributes these crossovers to phase-sensitive Andreev reflection processes that convert normal current into Andreev resonances with nonequilibrium populations. Our findings advance the understanding of quantum transport in hybrid superconducting systems and pave the way towards their applications in quantum technologies.