Gauge theories and phase transitions: from graphene to high-precision on supercomputers

par Simon Metayer (LAPTh Annecy)

mardi 17 mars 2026, 14:00 → 15:00 Europe/Paris

Amphi Besse

Many computational tools developed in particle physics for high-precision calculations can also be applied to problems in condensed matter, in particular to interaction-driven phase transitions. In this talk I will discuss how standard field-theory techniques based on multi-loop Feynman diagrams, large symbolic codes, and automated workflows running on supercomputers can be adapted to unconventional quantum field theories. Such systems may live in unusual dimensions or lack familiar properties such as unitarity or Lorentz invariance, requiring standard particle-physics tools to be adapted or redeveloped. As a use case, I will focus on graphene. At low energies it can be described by a form of QED in reduced dimensions, where planar relativistic electrons interact through non-local photons. I will present perturbative and non-perturbative approaches to this problem, including higher-loop computations and self-consistent Schwinger–Dyson equations, aimed at understanding interaction-driven phenomena such as a possible metal-to-insulator transition, which could be important for the future development of graphene based transistors. Finally, I will briefly discuss extensions of these ideas, including supersymmetric generalisations of this model and related computations of graphene’s mechanical properties. I will also mention ongoing work on large numerical implementations of non-perturbative approaches such as the S-matrix bootstrap, and discuss how these computational methods can be applied more broadly to strongly interacting gauge theories.