Renormalized band structure of Sr₂RuO₄: A quasiparticle tight-binding approach

We derive an effective quasiparticle tight-binding model which is able to describe with high accuracy the low-energy electronic structure of Sr ₂RuO₄ obtained by means of low temperature angle resolved photoemission spectroscopy. Such an approach is applied to determine the momentum and orbital dependent effective masses and velocities of the electron quasiparticles close to the Fermi level. We demonstrate that the model can provide, among the various computable physical quantities, a very good agreement with the experimentally measured specific heat coefficient and compares well with the plasma frequency estimated from local density calculations. Its use is underlined as a realistic input in the analysis of the possible electronic mechanisms related to the superconducting state of Sr₂RuO ₄.