  We investigate patterns of critical current as a function of perpendicular
and in-plane magnetic fields in superconductor-semiconductor-superconductor
(SNS) junctions based on InAs/InGaAs heterostructures with an epitaxial Al
layer. This material system is of interest due to its exceptionally good
superconductor-semiconductor coupling, as well as large spin-orbit interaction
and g-factor in the semiconductor. Thin epitaxial Al allows the application of
large in-plane field without destroying superconductivity. For fields
perpendicular to the junction, flux focusing results in aperiodic node spacings
in the pattern of critical currents known as Fraunhofer patterns by analogy to
the related interference effect in optics. Adding an in-plane field yields two
further anomalies in the pattern. First, higher order nodes are systematically
strengthened, indicating current flow along the edges of the device, as a
result of confinement of Andreev states driven by an induced flux dipole;
second, asymmetries in the interference appear that depend on the field
direction and magnitude. A model is presented, showing good agreement with
experiment, elucidating the roles of flux focusing, Zeeman and spin-orbit
coupling, and disorder in producing these effects.
