The occurrence of a Mott-like gap in single-particle spectra of electron systems possessing flat bands
V. A. Khodel
National Research Centre Kurchatov Institute, 123182 Moscow, Russia
McDonnell Center for the Space Science and Department of Physics
& Department of Physics, Washington University, St. Louis, MO 63130, USA
Abstract
An unconventional type of the Mott's insulators where the gap
in the spectrum of single-particle excitations is associated with
repulsive effective interactions between quasiparticles is shown to
exist in strongly correlated electron systems of solids that possess flat
bands. The occurrence of this gap is demonstrated to be the consequence
of violation of particle-hole symmetry, inherent in such systems. The
results obtained are
applied to elucidate the Fermi arc structure observed at
temperatures up to 100 K in angle-resolved photoemission spectra
of the compound Sr2IrO4, not showing superconductivity down
to low T.