2026/02/28 by Tommaso Maria Mazzocchi, Markus Aichhorn, Enrico Arrigoni
Physics and Astronomy · #cond-mat.str-el
11 pages, 4 figures. Version amended after first revision round--not yet published. Data repository accessible at https://repository.tugraz.at/records/rvb2z-3sf94
arxiv created 2026/07/30 · arxiv updated 2026/07/31
We present the mixed-configuration approximation (MCA) based on the auxiliary master equation approach impurity solver to study multiorbital correlated systems under equilibrium and nonequilibrium conditions within dynamical mean-field theory (DMFT). We benchmark the method for bulk and layered SrVO3 in equilibrium and apply it to a prototypical nonequilibrium geometry in which a voltage bias is applied perpendicular to the layer via reservoirs held at different chemical potentials. For bulk SrVO3, MCA reproduces the metallic state at moderate interaction strengths, but it overestimates the weight of the lower band relative to quantum Monte Carlo (QMC) and fork tensor product state (FTPS) solvers. With respect to QMC and FTPS, MCA yields an earlier metal-to-insulator transition as the electron-electron interaction is increased. In layered SrVO3 at equilibrium, MCA partially captures the orbital polarization in favor of the in-plane xy orbital, although not as strong as in the DMFT-converged results obtained with QMC. Finally, under applied bias, we observe a pronounced redistribution of orbital occupations, demonstrating that the method captures bias-driven orbital charge transfer in realistic materials in nonequilibrium conditions.