Abstract:
Recent research demonstrate many interesting phenomena on monolayer transition metal dichalcogenides (TMDs), including a direct band gap at visible frequency range, exotic physical properties associated with the valley degeneracy of carriers, and the existence of tightly bound exciton and trion. These properties imply rich opportunities for optical control of single electron spin in a TMD quantum dot similar to the extensively studied GaAs quantum dot systems, as well as appealing new possibilities of quantum control. To utilize these schemes, we first need to understand behaviour of neutral and charged excitons in a quantum dot and on a lateral heterojunction. We have employed effective mass approximation to investigate an interface exciton. We are also employing a tight-binding approach on the same problem with the ultimate goal of studying both exciton and trion properties at a TMD lateral heterojunction. We also outline the approach to use the tight-binding model to study excitons localized in a TMD quantum dot.