Interaction driven many-body phases of optically generated exciton ensembles in van der Waals heterostructures

• Applicants: Professor Dr. Alexander Walter Holleitner; Professorin Dr. Ursula Wurstbauer
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 290642686

The aim of the proposal is to examine the phase diagram and the phase transitions of strongly interacting exciton ensembles in van der Waals heterostructures at lowest temperatures and high exciton densities. In particular, the ground state properties of the individual phases shall be identified by their specific fingerprint, i.e. the low-energy excitation spectrum. The van der Waals heterostructures will be characterized and optimized, both in terms of the quality of the interfaces and the underlying electronic band structures. Based on a concerted experimental methodology and the expertise of the applicants, the proposal aims to answer which exciton phases show correlated behavior depending on temperature, exciton density and the density of coexisting electron or hole ensembles. Furthermore, the nature of the ground state of the individual phases will be fundamentally investigated. The critical parameters of van der Waals heterostructures shall be optimized in order to host correlated ensembles of dipolar excitons, e.g. in a Bose-Einstein condensate. The fundamental properties of the many-body states will characterized and researched for possible condensate-based quantum technology applications.

• DFG Programme: Research Grants