This study reports the observation of bipolar supercurrent in graphene, a two-dimensional material with unique electronic properties. The researchers investigated the Josephson effect in graphene, which involves the flow of supercurrent through a normal conductor between two superconducting electrodes. They fabricated graphene Josephson junctions using mechanical exfoliation and electron beam lithography, and observed supercurrents that depend on the gate voltage, with electrons or holes carrying the current in the conduction or valence band, respectively. Importantly, they found that a finite supercurrent can flow at zero charge density, indicating the presence of phase coherent electronic transport at the Dirac point. The Josephson effect in graphene was confirmed through measurements of current-voltage characteristics, showing a supercurrent without resistance below the critical current. The supercurrent was found to be robust, with oscillations in the critical current indicating a uniform supercurrent density distribution. The study also observed Shapiro steps, a signature of the ac Josephson effect, and subgap structures in the differential resistance due to multiple Andreev reflections, confirming the presence of induced superconductivity. The researchers analyzed the gate voltage dependence of the critical current and found a correlation between the critical current and the normal state conductance. They observed that the product of the critical current and the normal state resistance was close to the theoretical value for a ballistic graphene system. The study also highlighted the special role of time-reversal symmetry in graphene, where the presence of a superconducting electrode provides an intrinsic mechanism for coupling phase coherent electronic states from opposite valleys. The findings demonstrate the unique electronic properties of graphene, including phase coherent transport and the robustness of the Josephson effect. The study provides insights into the behavior of supercurrents in graphene and highlights the importance of time-reversal symmetry in the electronic structure of this material.This study reports the observation of bipolar supercurrent in graphene, a two-dimensional material with unique electronic properties. The researchers investigated the Josephson effect in graphene, which involves the flow of supercurrent through a normal conductor between two superconducting electrodes. They fabricated graphene Josephson junctions using mechanical exfoliation and electron beam lithography, and observed supercurrents that depend on the gate voltage, with electrons or holes carrying the current in the conduction or valence band, respectively. Importantly, they found that a finite supercurrent can flow at zero charge density, indicating the presence of phase coherent electronic transport at the Dirac point. The Josephson effect in graphene was confirmed through measurements of current-voltage characteristics, showing a supercurrent without resistance below the critical current. The supercurrent was found to be robust, with oscillations in the critical current indicating a uniform supercurrent density distribution. The study also observed Shapiro steps, a signature of the ac Josephson effect, and subgap structures in the differential resistance due to multiple Andreev reflections, confirming the presence of induced superconductivity. The researchers analyzed the gate voltage dependence of the critical current and found a correlation between the critical current and the normal state conductance. They observed that the product of the critical current and the normal state resistance was close to the theoretical value for a ballistic graphene system. The study also highlighted the special role of time-reversal symmetry in graphene, where the presence of a superconducting electrode provides an intrinsic mechanism for coupling phase coherent electronic states from opposite valleys. The findings demonstrate the unique electronic properties of graphene, including phase coherent transport and the robustness of the Josephson effect. The study provides insights into the behavior of supercurrents in graphene and highlights the importance of time-reversal symmetry in the electronic structure of this material.