Correlators on the wall and sln spin chain

We study algebras and correlation functions of local operators at half-BPS interfaces engineered by the stacks of D5 or NS5 branes in the 4D N=4 super Yang–Mills. The operator algebra in this sector is isomorphic to a truncation of the Yangian Y(gln). The correlators, encoded in a trace on the Yangian, are controlled by the inhomogeneous sln spin chain, where n is the number of fivebranes: they are given in terms of matrix elements of transfer matrices associated with Verma modules or, equivalently, of products of Baxter’s Q-operators. This can be viewed as a novel connection between the N=4 super Yang–Mills and integrable spin chains. We also remark on analogous constructions involving half-BPS Wilson lines.