We discover that the multiple degrees of freedom associated with magnetic skyrmions: size, position, and chirality, can all be used to control the Josephson effect and 0-pi transitions occurring in superconductor/magnetic skyrmion/superconductor junctions. In the presence of two skyrmions, the Josephson effect depends strongly on their relative chirality and leads to the possibility of a chirality-transistor effect for the supercurrent where the critical current is changed by several orders of magnitude simply by reversing the chirality of a magnetic skyrmion. Moreover, we demonstrate that the Fraunhofer pattern can show a local minimum at zero flux as a direct result of the skyrmion magnetic texture. These findings demonstrate the rich physics that emerges when combining topological magnetic objects with superconductors and could lead to new perspectives in superconducting spintronics.

5 pages, 5 figures