Polaritonic and excitonic semiclassical time crystals based on TMDC strips in an external periodic potential.

We investigated the dynamics of Bose-Einstein condensates (BECs) under an external periodic potential. We consider two such systems, the first being made of exciton-polaritons in a nanoribbon of transition metal dichalcogenides (TMDCs), such as MoSe[Formula: see text], embedded in a microcavity with a spatial curvature, which serves as the source of the external periodic potential. The second, made of bare excitons in a nanoribbon of twisted TMDC bilayer, which naturally creates a periodic Moiré potential that can be controlled by the twist angle.

Superfluidity of Dipolar Excitons in a Double Layer of - with a Mass Term.

We predict Bose-Einstein condensation and superfluidity of dipolar excitons, formed by electron-hole pairs in spatially separated gapped hexagonal α-T3 (GHAT3) layers. In the α-T3 model, the AB-honeycomb lattice structure is supplemented with C atoms located at the centers of the hexagons in the lattice. We considered the α-T3 model in the presence of a mass term which opens a gap in the energy-dispersive spectrum.