A new AI-MI–supported study reconstructs the theory of MgB₂ — the phonon-mediated superconductor with the highest known critical temperature, roughly 39 K — from minimal ab initio input. In “Quantum geometry and critical temperature enhancement in MgB₂ superconductivity,” the authors construct compact analytic models of the material’s electrons, phonons, and electron–phonon coupling. They show that strong in-plane boron sp² bonding produces an obstructed band structure whose natural description is a bond-centered kagome lattice, and that quantum-geometric contributions to the electron–phonon coupling help account for the material’s high transition temperature — results that point toward a transparent, symmetry-based account of superconductivity in MgB₂ and a route to doping trends in phonon-mediated superconductors more generally.
Three AI-MI investigators are among the co-authors: Emilia Morosan (Rice University), Leslie Schoop (Princeton University), and B. Andrei Bernevig (Princeton University, senior author), working with colleagues at DIPC, the Max Planck Institute for Chemical Physics of Solids, Aalto University, among others.
Source: arXiv:2607.19458