Quasiparticle dispersion and heat capacity of Na0.3CoO2: A dynamical mean-field theory study

We use the dynamical mean-field theory to calculate the Fermi surface and heat capacity for Na0.3CoO2. We resolve the conflicting outcomes of previous calculations by demonstrating that the nature of the calculated Fermi surface depends sensitively upon the bare Hamiltonian, and, in particular, the crystal-field splitting. By calculating both the Fermi surface and the heat capacity, we show that the only conclusion consistent with angle-resolved photoemission and heat capacity measurements is that the eg′ pockets are not present at the Fermi surface.