Electronic structure of transition metal-trihalide based van der Waals heterostructures

• Applicant: Dr. Andreas Koitzsch
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 456702393

Heterostructures made of 2D material years attracted considerable scientific attention in the last years. Recently the field received an additional boost by the discovery of magnetic 2D materials and of the outstanding properties of twisted bilayer graphene. Some 2D materials are considered potential candidates to overcome physical limitations of conventional semiconductor technology, which is becoming a bottleneck for advanced device manufacturing.The aim of the project is the investigation of the electronic structure of atomically thin transition metal halides such as Cr(Cl,Br,I)3 and RuCl3 and their heterostructures with graphene by means of photoemission spectroscopy. This should lead to a better understanding of their properties and the way external parameters influence these systems. While RuCl3 is a candidate for the realization of a quantum spin liquid, Cr(Cl,Br,I)3 retains magnetism down to the monolayer and is a promising material for nanoscale devices. In particular, heterostructures with graphene are an important building block of devices based on 2D materials. Knowledge of band alignment and hybridization effects is crucial for a thorough understanding of the interface properties. Charge transfer across the heterostructure may occur and modifications of the magnetic exchange parameters. Moreover, the electronic structure of heterobilayers and thin films may change even on a qualitative level when doped or after controlled defect creation.

• DFG Programme: Research Grants