Department of Physics and Astronomy

Dynamical Mean-Field Theory (DMFT)

The dynamical mean-field theory (DMFT) is a powerful technique to investigate strongly correlated systems. We apply and develop DMFT, in particular in combination with density-functional theory (DFT). We currently focus on methodological developments as well as applications to condensed matter physics and material science. The tool of choice for our activities is the full-potential linearized muffin-tin orbital (FP-LMTO)  code RSPt. RSPt includes a fully general DFT+DMFT implementation, with self-consistent cycles over self-energy and charge density. The following solvers are part of RSPt and were developed by our group:

  • spin-dependent T-matrix fluctuation-exchange (SPTF)
  • Hubbard I approximation (HIA)
  • Exact diagonalization (ED)

In RSPt, we also develop methods for extracting interatomic exchange interactions in correlated systems, for perfoming the analytycal continuation of Green's functions and self-energies, and for avoiding the problem of local minima in LDA+U. Currently we are working on methods to calculate X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS) for strongly correlated materials.

Among applications, we have applied our techniques to:

  • itinerant ferromagnets Fe, Co and Ni and their compounds
  • dilute magnetic semiconductors, as e.g. (Mn,Ga)As
  • transition metal oxides, as e.g. NiO and FeO
  • rare-earth compounds
  • multiferroics, as e.g. BiFeO3

Selected Publications