2015/03/22 by K. M. Stadler, A. Weichselbaum, Z. P. Yin +2 · 1 citation
Physics and Astronomy · #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.115.136401
published as Phys. Rev. Lett. 115, 136401 (2015) · 6 pages, 3 figures
arxiv created 2015/03/22 · arxiv updated 2015/09/30
We show that the numerical renormalization group (NRG) is a viable multi-band impurity solver for Dynamical Mean Field Theory (DMFT), offering unprecedent real-frequency spectral resolution at arbitrarily low energies and temperatures. We use it to obtain a numerically exact DMFT solution to the Hund's metal problem for a three-orbital model with filling factor nd=2. The ground state is a Fermi liquid. The one-particle spectral function has a strong particle-hole asymmetry, with a clear apparent power law for positive frequencies only. With increasing temperature it shows a coherence-incoherence crossover with spectral weight transfered from low to high energies and evolves qualitatively differently from a doped Mott insulator. The spin and orbital spectral functions show "spin-orbital separation": spin screening occurs at much lower energies than orbital screening. The renormalization group flows clearly reveal the relevant physics at all energy scales.