03/12/2024
A recent study by Stefano Pittalis of the Institute of nanoscience (Cnr-nano) and Tim Gould of the Queensland Micro- and Nanotechnology Centre, Griffith University, introduces a novel approach to modeling excited states in materials. Published in the prestigious journal PRX, the approach promises to improve the predictive power of computational methods in materials science, with potential implications for energy-efficient technologies such as photovoltaics.
At the core of the research are excitations in materials that can involve change of the quantum state of electrons via exchange of energy. Excitations of this type are at the center of technologies like photovoltaics by which the energy from light is converted into useful electricity. “To study quantum states in advanced materials, even in materials yet to be synthesized, computer calculations, such as those based on density functional theory (DFT), are essential,” Pittalis explains. “However, DFT is limited to the study of fundamental states, that is, those at low energy. For some time, many research groups have been working to overcome this obstacle and extend DFT methodologies to high-energy states, paving the way for a deeper understanding of the properties of materials.”
Researchers, Stefano Pittalis and Tim Gould, revisited the paradigmatic model of the homogeneous electron gas, a mainstay of density functional theory, and formulated the ensemble Local Density Approximation (eLDA), a novel extension of the already well-known Local Density Approximation (LDA), hat work also for excited states. “This new approach takes into account a previously neglected class of excited states of the homogeneous electron gas and uses it to model excitations in real materials,” Pittalis concludes.
The eLDA represents a significant step forward in extending the capabilities of DFT, as it allows not only fundamental states but also excited states to be described. This advance opens up new possibilities for more accurate simulations and a deeper understanding of the properties and behavior of materials.
Per informazioni:
Maddalena Scandola
Cnr-Nano
comunicazione@nano.cnr.it
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