▎ 摘　　要

Superconducting diodes are proposed nonreciprocal circuitelementsthat should exhibit nondissipative transport in one direction whilebeing resistive in the opposite direction. Multiple examples of suchdevices have emerged in the past couple of years; however, their efficiencyis typically limited, and most of them require a magnetic field tofunction. Here we present a device that achieves efficiencies approaching100% while operating at zero field. Our samples consist of a networkof three graphene Josephson junctions linked by a common superconductingisland, to which we refer as a Josephson triode. The three-terminalnature of the device inherently breaks the inversion symmetry, andthe control current applied to one of the contacts breaks the time-reversalsymmetry. The triode's utility is demonstrated by rectifyinga small (nA scale amplitude) applied square wave. We speculate thatdevices of this type could be realistically employed in the modernquantum circuits.