Wigner crystalline in PbS moiré superlattices

  Recently, moiré superlattices of twisted van der Waal (vdW) materials have attracted a giant interest due to a series of breakthroughs. Since the quantum confinement from vdW interaction is not strong enough due to the weak interaction, a series of important properties are missed. Strong reconstruction and deep energy levels are desired due to the potential applications in devices and novel physics different from vdW layers. Benefited from the strong interaction, we predict a new species of twisted nanosheets beyond vdW materials. Such a crazy structure is confirmed by our TEM experiment. Combined with DFT calculation, we find a series of strain vertex and dipole vertex at the interface. If the materials are doped with a low concentration of electrons, different phases of Wigner crystalline will form even without any magnetic field. These properties can be applied in novel devices.