Using a phenomenological Hamiltonian, we investigate the quasiparticle lifetimes and dispersions in the three low energy bands $\gamma$, $\beta$, and $\alpha$ of ${\mathrm{Sr}}_2\mathrm{Ru}{\mathrm{O}}_4$. Couplings in the Hamiltonian are fixed so as to produce the mass renormalization as measured in magneto-oscillation experiments. We thus find reasonable agreement in all bands between our computed lifetimes and those measured in angle resolved photoemission spectroscopy experiments by Kidd et al. [Phys. Rev. Lett. 94, 107003 (2005)] and Ingle et al. [Phys. Rev. B 72, 205114 (2005)]. In comparing the computed to measured quasiparticle dispersions, we, however, find good agreement in the $\alpha$ band alone.

• Received 16 November 2006

DOI:https://doi.org/10.1103/PhysRevB.76.104501