Enhanced triplet Andreev reflection off a domain wall in a lateral geometry

We find that the triplet Andreev reflection amplitude at the interface between a half-metal and an s-wave superconductor in the presence of a domain wall is significantly enhanced if the half-metal is coupled laterally to the superconductor. Whereas triplet Andreev reflection is absent at the Fermi energy in the case of serial coupling, it is nonzero in a lateral contact geometry. We also find that in the lateral case domain walls cause (Andreev) backscattering even in the adiabatic limit of long domain walls, contrary to adiabatic domain walls in ordinary magnetic systems. For a lateral contact, domain walls can thus be an effective source of the triplet proximity effect.