Point contacts provide simple connections between macroscopic particle
reservoirs. In electric circuits, strong links between metals, semiconductors
or superconductors have applications for fundamental condensed-matter physics
as well as quantum information processing. However for complex, strongly
correlated materials, links have been largely restricted to weak tunnel
junctions. Here we study resonantly interacting Fermi gases connected by a
tunable, ballistic quantum point contact, finding a non-linear current-bias
relation. At low temperature, our observations agree quantitatively with a
theoretical model in which the current originates from multiple Andreev
reflections. In a wide contact geometry, the competition between superfluidity
and thermally activated transport leads to a conductance minimum. Our system
offers a controllable platform for the study of mesoscopic devices based on
strongly interacting matter.Comment: 5 pages, 4 figures, 7 pages supplementar
