Competition of moiré network sites to form electronic quantum dots in reconstructed MoX${}_2$/WX${}_2$ heterostructures

Abstract

Twisted bilayers of two-dimensional semiconductors offer a versatile platform to engineer quantum states for charge carriers using moiré superlattice effects. Among the systems of recent interest are twistronic MoSe${}_2$/WSe${}_2$ and MoS${}_2$/WS${}_2$ heterostructures, which undergo reconstruction into preferential stacking domains and highly strained domain wall networks, determining the electron/hole localization across moiré superlattices. Here, we present a catalogue of options for the formation of self-organized quantum dots and wires in lattice-reconstructed marginally twisted MoSe${}_2$/WSe${}_2$ and MoS${}_2$/WS${}_2$ bilayers, fine tuned by the twist angle between the monolayers from perfect alignment to $\theta \sim 1^{\circ }$, and by choosing parallel or anti-parallel orientation of their unit cells. The proposed scenarios of the quantum dots and wires formation are found using multi-scale modelling that takes into account the features of strain textures caused by twirling of domain wall networks.

7 pages, 5 figures