In both nature and technology, electrons are constantly pushed out of equilibrium by external influences, such as light, electric fields or heat. The way in which they absorb energy, move and relax determines the performance of many of today’s devices, from optical sensors to communication systems. However, describing this behaviour remains highly theoretically challenging because real materials contain a wealth of structural and chemical imperfections, defects and disorder, which strongly influence, and sometimes fully dominate, the way electrons behave and propagate.

Researchers from the ICN2 Theoretical and Computational Nanoscience Group have developed a powerful new computational framework that can simulate complex electron behaviour in real time under highly realistic conditions. This new approach enables scientists to observe materials being driven out of equilibrium at unprecedented time and spatial scales, bridging the gap between theoretical modelling and real-world device conditions. This work, conducted by Dr Luis M. Canonico, ICREA Professor Stephan Roche, and Dr Aron W. Cummings, has been published in Physical Review Letters.

The team first applied this method to graphene, where the simulations reproduced its established optical behaviour perfectly in the clean case. More surprisingly, they revealed that a certain degree of electrostatic disorder can actually enhance light absorption, contrary to common sense. This opens new possibilities for optimising graphene-based photonic components. They then extended the approach to nanoporous graphene, a derivative form of graphene (first synthesised at ICN2 Atomic Manipulation and Spectroscopy Group), showing that even weak disorder can strongly amplify its anisotropic optical response. This brings promising implications for the development of direction-sensitive and tuneable sensors based on 2D materials platform.

Indeed, this framework can be applied to many different large-area materials with complex defect landscapes and in arbitrary dimensions, providing a versatile platform to explore far-from-equilibrium quantum physics under realistic conditions and to accelerate the development of next-generation optoelectronic and sensing devices.

Reference article:

Canonico, L.M; Roche, S; Cummings, A.W. Real-Time Out-of-Equilibrium Quantum Dynamics in Disordered Materials. Physical Review Letters. (2025). DOI: https://doi.org/10.1103/28hd-pwhv