ANR SUPERZIC : Graphene superlattice induced by zwitterions self-assembly

_{ANR SUPERZIC (2023-2026)}

Partners :

IM2NP (porteur, Marseille)
L2C (Montpellier)
CINaM (Marseille)

Context and Challenges

Stacking 2D materials to create a moiré effect is a recent method for modifying the band structure of van der Waals heterostructures. This can lead to the emergence of quasi-flat bands, promoting the appearance of quantum materials with strongly correlated electrons. However, these properties remain poorly understood and controlled.

Current Limitations

Current experiments use only inorganic heterostructures, where the modulation of the electrostatic potential is fixed by the 2D layers used.

Proposed Innovation

This project aims to replace an inorganic layer with a 2D self-assembly of zwitterionic organic molecules deposited on graphene. This would enable the creation of hybrid organic/inorganic heterostructures (h-vdW-H) whose lattice parameters and potential amplitude could be modulated.

Scientific Objectives

• Local Characterization: Investigate the impact of molecular dipoles on the electronic structure of graphene (electrostatic potential, electronic density, charge transfer, flat bands) using low-temperature local probe microscopy.

• Mesoscopic Characterization: Measure carrier doping and mobility via Hall effect and four-point probe measurements, under vacuum and at low temperature. Complement with Micro-Raman mapping to analyze vibrational responses and average graphene doping.

• Simulations: Model the electronic structure of the supramolecular pattern using ab initio calculations and simulate quantum transport properties.

The study seeks to identify the conditions for the emergence of flat bands and to detect possible signatures of strongly correlated electron systems in these hybrid heterostructures.

Summary The project explores a new approach to control the electronic properties of graphene through the self-assembly of zwitterionic molecules, combining local and mesoscopic experiments with theoretical simulations.