Over the next four years, the Instituto Superior Técnico, Universidade de Lisboa, will lead a consortium of the world’s top physics and computing centres in plasma physics to study “pair plasmas,” a unique state of matter composed of electrons and their antimatter counterparts, positrons. The project, Plasma Antimatter Investigation and Realisation (PAIR), has received funding through the European Union’s Horizon Europe programme.
For decades, the study of “pair plasmas” was mostly limited to theoretical calculations and distant telescope observations, given the exotic nature of this state of matter. This new European initiative led by Técnico aims to turn “pair plasmas” into a controllable laboratory reality.
“Europe has reached a turning point”, says Thomas Grismayer, Principal Investigator of the project developed and member of the Group of Lasers and Plasmas (GoLP) at the Institute for Plasmas and Nuclear Fusion (IPFN), a research unit affiliated with Técnico. “We have the laser power and the particle beams needed to generate these plasmas, and there is an outstanding opportunity to build a unified way to understand them”, he adds. “PAIR is designed to bridge this gap”, he clarifies.
The consortium is led by Técnico and includes the University of Oxford, Max-Planck-Institut, Sorbonne University, the University of California, Los Angeles (UCLA), the University of Rochester, and specialised companies such as ColibriTD and CERFACS. The initiative, under the Marie Skłodowska-Curie Actions, relies on a strategic exchange of staff between these entities.
AI and quantum tools played a key part in the discovery of this exotic plasma
Because the electrons and positrons have the same mass, the “pair plasmas” behave in ways that traditional physics rules cannot easily predict, making them fundamentally different. These plasmas are pervasive in the extreme environments found around pulsars and black holes, and controlled lab experiments by the PAIR project will provide a unique testing ground for the laws of physics under conditions we cannot find naturally on Earth.
Despite their importance to fundamental science, these antimatter clouds are notoriously difficult to maintain – they are often short-lived and hard to control. Leveraging facilities like the Apollon laser and CERN, the PAIR project will move beyond temporary demonstrations to create a reliable blueprint for generating the dense, long-lived ‘pair plasmas’ necessary for in-depth laboratory study.
Investigating these plasmas requires more than just high-energy hardware – it requires a massive leap in computing power. Current computer simulations of these processes are so complex that they often hit a wall in terms of cost and time. One of the project’s most innovative goals is the creation of a “digital engine” that uses scientific machine learning and prototype quantum algorithms to model plasma behaviour. By integrating these models, we expect to speed up these simulations, allowing us to validate our lab results against theory in real-time. The project also aims to train a generation of researchers who can move seamlessly between high-power laser physics and advanced software engineering.
As the project enters its 4-year mission, the focus will remain on delivering concrete, reusable assets: open-source software, benchmarked experimental designs, and a new framework for astrophysical interpretation. By the time the final conference of the project concludes, the consortium aims to have established a permanent capability for pair-plasma science in Europe, ensuring the continent remains at the frontier of high-energy-density physics.
