Skip to main content
The European High Performance Computing Joint Undertaking (EuroHPC JU)

Exciton-phonon-driven instabilities in layered materials

Awarded Resources (in node hours)
Leonardo Booster
System Partition
13 November 2024 - 12 November 2024
Allocation Period

Two-dimensional (2D) materials can assume novel, exotic condensed matter phases highly relevant for possible breakthroughs in nano- and opto- electronics, such as ultrafast (photo)transistors and detectors.

This project is about uncovering the mechanisms driving the stabilisation of charge density waves (CDW) in bulk molybdenum disulphide (MoS2), where a transition to a CDW phase has been predicted at low temperature and ultra-high hydrostatic pressure.

The project aims to reveal whether this phase is stabilised by the electron-hole interactions (excitons) or rather by the thermal vibrations of the crystal lattice, i.e., phonons. The two mechanisms compete in 2D systems, and the former case – called excitonic insulator – is more desirable for applications because the phase switching times are considerably faster. It will employ highly predictive, first-principles numerical methods – using two flagship codes of the EU MaX “Materials Science at the Exascale” Centre of Excellence ( – applied to phonons, excitons, and their interactions under extreme conditions.

This is a computationally demanding effort calling for efficient exploitation of large HPC resources. The project will calculate inelastic X-ray scattering spectra (IXS) of bulk MoS2 and focus on their pressure dependence in order to follow the pathways of both excitonic and phononic instabilities.