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 a thin film, rather than an extended magnet. The enhancement is by a factor $l_{\rm d}/d$, where $l_{\rm d}$ is the width of the domain wall and $d$ the film thickness. We conclude that in a lateral geometry, domain walls can be an effective source of the triplet proximity effect.