Crystal phases of charged interlayer excitons in van der Waals heterostructures

Throughout the years, strongly correlated coherent states of excitons have been the subject of intense theoretical and experimental studies. This topic has recently boomed due to new emerging quantum materials such as van der Waals (vdW) bound atomically thin layers of transition metal dichalcogenides (TMDs). We analyze the collective properties of charged interlayer excitons observed recently in bilayer TMD heterostructures. We predict strongly correlated phases-crystal and Wigner crystal-that can be selectively realized with TMD bilayers of properly chosen electron-hole effective masses by just varying their interlayer separation distance. Our results can be used for nonlinear coherent control, charge transport and spinoptronics application development with quantum vdW heterostuctures. Low-dimensional transition metal dichalcogenides are an ideal platform to investigate strongly correlated phenomena with excitons. Here, the authors theoretically demonstrate that bilayer heterostructures of these materials can be used to realize the strongly correlated many-particle states of charged interlayer excitons that can be controlled by the interlayer separation adjustment and can be tuned by both electro- and magneto-static external fields.