Nonlinear circular valley photogalvanic effect

We develop a theory of circular photogalvanic effect in non-gyrotropic two-dimensional transition metal dichalcogenide monolayers under interband optical transitions. Oblique incidence circularly-polarized electromagnetic field or normal elliptically polarized is assumed. In contrast to the linear-in-intensity conventional effect, considered here arises second intensity order. The conditioned by i) predominant population valleys in-plane component and ii) direct drift photo-excited carriers linear-polarized presence trigonal valley asymmetry.