Correlated Electronic Structure of La_{3}Ni_{2}O_{7} under Pressure
Viktor Christiansson1, Francesco Petocchi2, Philipp Werner1
1Department of Physics, University of Fribourg, 1700 Fribourg, Switzerland.
Abstract:
Recently, superconductivity with a T_{c} up to 78 K has been reported in bulk samples of the bilayer nickelate La_{3}Ni_{2}O_{7} at pressures above 14 GPa. Important theoretical tasks are the formulation of relevant low-energy models and the clarification of the normal state properties. Here, we study the correlated electronic structure of the high-pressure phase in a four-orbital low-energy subspace using different many-body approaches: GW, dynamical mean field theory (DMFT), extended DMFT (EDMFT) and GW+EDMFT, with realistic frequency-dependent interaction parameters. The nonlocal correlation and screening effects captured by GW+EDMFT result in an instability toward the formation of charge stripes, with the 3d_{z^{2}} as the main active orbital. We also comment on the potential relevance of the rare-earth self-doping pocket, since hole doping suppresses the ordering tendency.
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