Low-temperature electronic properties of ${\mathrm{Sr}}_2{\mathrm{RuO}}_4.$ I. Microscopic model and normal-state properties

Starting from the quasi-one-dimensional kinetic energy of the $d_{\mathrm{yz}}$ and $d_{\mathrm{zx}}$ bands we derive a bosonized description of the correlated electron system in ${\mathrm{Sr}}_2{\mathrm{RuO}}_4.$ At intermediate coupling the magnetic correlations have a quasi-one-dimensional component along the diagonals of the basal plane of the tetragonal unit cell that accounts for the observed neutron scattering results. Together with two-dimensional correlations the model consistently accounts for the normal phase specific heat, cyclotron mass enhancement, static susceptibility, and Wilson ratio and implies an anomalous high-temperature resistivity.