  Recently it has been predicted that the Andreev bound state spectrum of
4-terminal Josephson junctions may possess zero-energy Weyl singularities.
Using one superconducting phase as a control parameter, these singularities are
associated with topological transitions between time-reversal symmetry broken
phases with different Chern numbers. Here we show that such topological
transitions may also be tuned with a magnetic flux through the junction area in
a 3-terminal geometry.
