Pseudogaps in the t−J model: An extended dynamical mean-field theory study
Kristjan Haule, Achim Rosch, Johann Kroha +1 more
We investigate the highly incoherent regime of hole-doped two-dimensional Mott-Hubbard insulators at moderately small doping $\ensuremath{\delta}$ and temperatures $\ensuremath{\gtrsim}0.1J,$ where J is the exchange coupling. Within an extended dynamical mean-field theory of the $t\ensuremath{-}J$ model and a generalized noncrossing approximation we calculate the single-particle spectral function, the dynamical susceptibility, and thermodynamic and transport quantities. Short-ranged antiferromagnetic fluctuations lead to strongly incoherent single-particle dynamics, large entropy, and large electrical resistivity. At low doping a pseudogap is found to open up in both the single-particle and spin excitation spectra, leading to a decrease in entropy and resistivity. The Hall coefficient changes sign to positive values upon lowering the doping level and increases inversely proportional to $\ensuremath{\delta}.$
arXiv:cond-mat/0304096•Physical review. B, Condensed matter•Oct 28, 2003•49 citations