Anisotropic exciton transport in transition-metal dichalcogenides

Due to the intervalley exchange interaction exciton eignestates in monolayer transitional metal dichalcogenides are coherent superposition of two valleys. The branch which couples with transverse electric linearly polarized light has parabolic dispersion in terms of it center of mass momentum, whereas the one which couples to transverse magnetic has both parabolic and linear components. While the dispersion of excitons is well established theoretically there is no experimental verification of the linear component of the dispersion up to date. In this talk we present experimentally realizable method for unambiguous observation of the signature of linear component of the dispersion. In particular, we will demonstrate that by pumping the system with linearly polarized light the exciton transport is anisotropic compared to circularly polarized pump and this feature is special for this specific type of dispersion. This signature is present also for positively detuned exciton-polaritons and for reasonable level of disorder. Therefore, this opens the possibility for experimental identification of the peculiar structure of exciton dispersion of transition metal dichalcogenides.