The role of dynamical screening in correlated materials

CFEL Theory Seminar

  • Datum: 03.02.2016
  • Uhrzeit: 14:00 - 15:00
  • Vortragende(r): Ferdi Aryasetiawan
  • Lund University, Sweden
  • Ort: CFEL (Bldg. 99)
  • Raum: Seminar Room IV, O1.111
  • Gastgeber: Angel Rubio
The role of dynamical screening in correlated materials
A physically motivated approach for studying the electronic structure of strongly correlated materials is to focus on a subspace of the full Hilbert space containing most of the relevant correlation effects. The reduction to a limited subspace results in an energy-dependent effective electron-electron interaction U. It was not until recently an impurity problem with dynamic U could be solved within dynamical meanfield theory (DMFT) using continuous-time quantum Monte Carlo technique. The energy dependence of U can have unexpected consequences. As an illustration, we consider La2CuO4, the prototype of hightemperature superconductor parent compounds. DMFT calculations on undoped La2CuO4 show the important role of dynamic U: starting from the local density band structure, the insulating state is not obtained when a static U calculated from first-principles is used. Analysis of U and the DMFT spectral functions leads to a new insight into the nature of the electronic structure of charge-transfer insulators to which La2CuO4 belongs.
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