  We initiate the calculation of quantum corrections to Wilson loops in a class
of four-dimensional defect conformal field theories with vacuum expectation
values based on N=4 super Yang-Mills theory. Concretely, we consider an
infinite straight Wilson line, obtaining explicit results for the one-loop
correction to its expectation value in the large-N limit. This allows us to
extract the particle-interface potential of the theory. In a further
double-scaling limit, we compare our results to those of a previous calculation
in the dual string-theory set-up consisting of a D5-D3 probe-brane system with
flux, and we find perfect agreement.
