Metanematic transitions in a bilayer system: Application to the bilayer ruthenate

摘要

It was suggested that the two consecutive metamagnetic transitions and the large residual resistivity discovered in Sr_3Ru_2O_7 can be understood via the nematic order and its domains in a single layer system. However, a recently reported anisotropy between two longitudinal resistivities induced by tilting the magnetic field away from the c axis cannot be explained within the single layer nematic picture. To fill the gap in our understanding within the nematic order scenario, we investigate the effects of bilayer coupling and in-plane magnetic field on the electronic nematic phases in a bilayer system. We propose that the in-plane magnetic field in the bilayer system modifies the energetics of domain formation, since it breaks the degeneracy of two different nematic orientations. Thus, the system reveals a pure nematic phase with a resistivity anisotropy in the presence of an in-plane magnetic field. In addition to the nematic phase, the bilayer coupling opens a different route to a hidden nematic phase that preserves the x-y symmetry of the Fermi surfaces.