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RESEARCH PRODUCT

Magnetic phase diagram of the anisotropic multi-band Hubbard model

C. KnechtP. G. J. Van DongenN. Blümer

subject

Condensed Matter::Quantum GasesPhysicsHubbard modelCondensed matter physicsQuantum Monte Carlomedia_common.quotation_subjectPhase (waves)FrustrationCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsMott transitionAntiferromagnetismCondensed Matter::Strongly Correlated ElectronsPerturbation theoryGround statemedia_common

description

Using quantum Monte Carlo (QMC) simulations we determine the magnetic phase diagram of the anisotropic two-band Hubbard model within the dynamical mean-field theory (DMFT) in the important intermediate-coupling regime. We compare the QMC predictions with exact results from second-order weak-and strong-coupling perturbation theory. We find that the orbital-selective Mott transition (OSMT), which occurs in the fully frustrated case, is completely hidden in the antiferromagnetic (AF) ground state of the model. On the basis of our results, we discuss possible mechanisms of frustration. We also demonstrate the close relationship of the physics of the two-band Hubbard model in the orbital-selective Mott (OSM) phase to the Falicov-Kimball model.

https://doi.org/10.1002/pssb.200674632