Dynamic Jahn-Teller Mechanism of Superconductivity in MgB₂

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We propose a novel mechanism of superconductivity in MgB₂ based on the dynamic electronic structure of the pσ-orbitals coupled with e₂g phonons. A nonconventional superconducting state is found to arise frome lectron-phonon interactions in the presence of additional pairing channels made available by the dynamic Jahn-Teller effects. A partially broken pseudo-spin symmetry in this Jahn-Teller system, together with two-phonon exchange pairing, naturally gives rise to two distinct gaps both of which are basically isotropic in the (kₓ, ky) space. Important experimental observations including high Tc and the anomalous specific heat are explained using this theory.