The Fermi surface and the role of electronic correlations in Sm(2-x)Ce(x)CuO4.

ABSTRACT

Using a LDA+GTB (local density approximation+generalized tight-binding) hybrid scheme we investigate the band structure of the electron-doped high- T(c) material Sm(2-x)Ce(x)CuO(4). Parameters of the minimal tight-binding model for this system (the so-called three-band Emery model) were obtained within the NMTO (Nth-order muffin-tin orbital) method. The doping evolution of the dispersion and the Fermi surface in the presence of electronic correlations was investigated in two regimes of magnetic order short-range (spin-liquid) and long-range (antiferromagnetic metal). Each regime is characterized by the specific topologies of the Fermi surfaces and we discuss their relation to recent experimental data.