Four-dimensional $\mathcal{ N}=4$ super Yang-Mills theory admits interfaces that preserve integrability of the theory. It was shown that addition of fundamental hypermultiplets living on a co-dimension one defect is an example of such an interface. We consider NS5 interface as a different example of half-BPS defect in this theory and prove that integrability is generically broken already at one loop. We show that one-loop dilatation operator acting on boundary local operators does not lead to an integrable spin chain. The same is true also for D5-like and NS5-like boundaries.
Categories: hep-th math-ph math.MP