  Hybrid InSb nanowire-superconductor devices are promising for investigating
Majorana modes and topological quantum computation in solid-state devices. An
experimental realisation of ballistic, phase-coherent superconductor-nanowire
hybrid devices is a necessary step towards engineering topological
superconducting electronics. Here, we report on a low-temperature transport
study of Josephson junction devices fabricated from InSb nanowires grown by
molecular-beam epitaxy and provide a clear evidence for phase-coherent,
ballistic charge transport through the nanowires in the junctions. We
demonstrate that our devices show gate-tunable proximity-induced supercurrent
and clear signatures of multiple Andreev reflections in the differential
conductance, indicating phase-coherent transport within the junctions. We also
observe periodic modulations of the critical current that can be associated
with the Fabry-P\'{e}rot interference in the nanowires in the ballistic
transport regime. Our work shows that the InSb nanowires grown by
molecular-beam epitaxy are of excellent material quality and hybrid
superconducting devices made from these nanowires are highly desirable for
investigation of the novel physics in topological states of matter and for
applications in topological quantum electronics.
