Quasiparticle interference in the unconventional metamagnetic compound Sr3Ru2O7

Quasiparticle interference (QPI) in spectroscopic imaging scanning tunneling microscopy provides a powerful method to detect orbital band structures and orbital ordering patterns in transition-metal oxides. We use the T-matrix formalism to calculate the QPI spectra for the unconventional metamagnetic system of Sr3Ru2O7 with a t(2g)-orbital band structure. A detailed tight-binding model is constructed accounting for features such as spin-orbit coupling, bilayer splitting, and the staggered rotation of the RuO octahedra. The band parameters are chosen by fitting the calculated Fermi surfaces with those measured in the angular-resolved photoemission spectroscopy experiment. The calculated quasiparticle interference at zero magnetic field exhibits a hollow squarelike feature arising from the nesting of the quasi-one-dimensional d(xz) and d(yz) orbital bands, in agreement with recent measurements by Lee et al. [Nat. Phys. 5, 800 (2009)]. Rotational symmetry breaking in the nematic metamagnetic state also manifests in the quasiparticle interference spectra.