Project Details
Projekt
Quantum gases in moiré-ordered and reconstructed heterostructures: effective dimensionalities, hybrid states, and interactions
Applicants
Professor Dr. Alexey Chernikov; Professor Dr. Alexander Högele; Dr. Alexander Steinhoff-List
Subject Area
Experimental Condensed Matter Physics
Theoretical Condensed Matter Physics
Theoretical Condensed Matter Physics
Term
since 2020
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 443405595
Van der Waals heterostructures of twisted or lattice-mismatched two-dimensional transition metal dichalcogenides emerged as rich and versatile platforms for optical studies of many-particle and correlated electron physics. These types of phenomena depend sensitively on the specific material configurations, including lattice and angular mismatch leading to the formation of moiré-superlattices or locally and mesoscopically reconstructed domains. While offering a high level of flexibility and tunability for the design of the electronic many-particle states, it also demands accurate descriptions of the underlying fundamental processes. This motivates the main goal of this project to develop comprehensive understanding of the many-body physics in semiconducting van der Waals heterostructures governing their optical response across linear and non-linear regimes. We will address a broad range of density conditions for both bosonic and fermionic types of quasiparticles, such as excitons or electron-hole plasma and their mixtures. Specifically, we aim to understand the impact of dimensionality from effectively two-, one-, and zero-dimensional domains in reconstructed heterostructures on the dynamics and transport of optical excitations, using a unified material platform for all relevant quantum confinement regimes from low to high densities. In addition, we will create and control hybrid, interacting moiré exciton states combining strong exciton-exciton and exciton-photon interactions towards tunable dipolar polaritonics. Finally, we plan to develop experimental and theoretical approaches to externally manipulate both the strength and sign of the exciton-exciton interactions from repulsive to attractive, as well as crossing the border between pure Bose and Fermi gases to trigger formation of distinct many-body phases on demand. To address these goals, we will combine state-of-the art sample fabrication techniques with advanced experimental methods including hyperspatial and magneto-spectroscopy, ultrafast transient microscopy, and structural characterization, as well as microscopic many-body theory of electronic and optical properties up to high density regimes. Ultimately it will allow us to address topical questions on the forefront of a rapidly growing research field towards key scientific and technological advances in the broad area of two-dimensional van der Waals heterostructures.
DFG Programme
Priority Programmes
