Breakdown of Luttinger's theorem in two-orbital Mott insulators
- 181 Downloads
An analysis of Luttinger's theorem shows that – contrary to recent claims – it is not valid for a generic Mott insulator. For a two-orbital Hubbard model with two electrons per site the crossover from a non-magnetic correlated insulating phase (Mott or Kondo insulator) to a band insulator is investigated. Mott insulating phases are characterized by poles of the self-energy and corresponding zeros in the Greens functions defining a “Luttinger surface” which is absent for band insulators. Nevertheless, the ground states of such insulators with two electrons per unit cell are adiabatically connected.
PACS.71.10.-w Theories and models of many-electron systems 71.10.Fd Lattice fermion models (Hubbard model, etc.) 71.30.+h Metal-insulator transitions and other electronic transitions
Unable to display preview. Download preview PDF.
- J. Ortloff, M. Balzer, M. Potthoff, Eur. Phys. J. B 58, (2007) 37. Google Scholar
- J. Hubbard, Proc. R. Soc. (London), Ser. A 276, 238 (1963) Google Scholar
- W. Jones, N.H. March, Theoretical Solid State Physics, Vol. 1 (John Wiley & Sons, London, 1973) Google Scholar
- M. Potthoff, Condens. Mat. Phys. 9, 557 (2006) Google Scholar
- The non-analytic kinks in Figure 2 are a trivial artifact of the non-analytic dependence of the bare coupling constants on λ. They do therefore not signal a quantum phase transition Google Scholar