Orbital-selective Mott transitions in the anisotropic two-band Hubbard model at finite temperatures

Knecht, C.; Blümer, N.; van Dongen, P. G. J.

Orbital-selective Mott transitions in the anisotropic two-band Hubbard model at finite temperatures

Authors

Knecht, C.

Blümer, N.

van Dongen, P. G. J.

Description

The anisotropic degenerate two-orbital Hubbard model is studied within dynamical mean-field theory at low temperatures. High-precision calculations on the basis of a refined quantum Monte Carlo (QMC) method reveal that two distinct orbital-selective Mott transitions occur for a bandwidth ratio of 2 even in the absence of spin-flip contributions to the Hund exchange. The second transition -- not seen in earlier studies using QMC, iterative perturbation theory, and exact diagonalization -- is clearly exposed in a low-frequency analysis of the self-energy and in local spectra.
4 pages, 5 figures