Tuning electronic properties in twisted 2d transition metal dichalcogenides heterostructures.
The emergence of graphene in 2004 gave rise to the isolation of a new  myriad of 2D materials with many different properties. In addition, the stacking of different 2D layers, forming Van der Waals heterostructures,  has shown the possibility to modify and expand the features of the final hybrid materials. An important ingredient for the final attributes of these heterostructures is the alignment of its constituents. As a consequence of the difference in lattice constant and the relative angle between the 2D layers, a moiré pattern arises. This moiré pattern can give rise to new physics not present in the original materials. This has already being proven in twisted graphene heterostructures, and its study is exploding in popularity these days.
On the other hand, twisted heterostructures of semiconducting TMDs have received less attention. This project aims to realise and understand new correlated electronic phases of matter in twisted heterostructures of atomically thin semiconductors. Specifically, the project aims to: (1) thoroughly characterize the electronic structure of twisted semiconductor heterostructures; (2) understand how correlated electronic phases arise from interactions in twisted semiconductor heterostructures; and (3) search for new electronic phases such as spin liquids and topological phases. These new electronic phases will radically alter the conductivity of the heterostructure, and are expected to be highly sensitive to the electron density in the moiré superlattice and hence can be tuned via electronic gates, creating novel low-energy switches. The heterostructures will be characterised using electronic measurements, and low temperature scanning probe microscopy and spectroscopy measurements. While this fellowship would allow the experienced researcher to learn new techniques and expand his knowledge and networks, the topic of this proposal is also in line with the goals of Horizon 2020, Graphene Flagship and Quantum Flagship EU programmes.