Pseudogaps in the t-J model: Extended DMFT study

TL;DR

This study uses extended DMFT to analyze the pseudogap phenomena in the t-J model, revealing incoherent dynamics, entropy, resistivity behaviors, and a doping-dependent Hall coefficient in hole-doped 2D Mott insulators.

Contribution

It provides a detailed theoretical investigation of pseudogap formation and transport properties in the t-J model using extended DMFT and non-crossing approximation methods.

Findings

Pseudogap opens at low doping in spectral and spin spectra.

Incoherent single-particle dynamics and high resistivity are observed.

Hall coefficient becomes positive and inversely proportional to doping.

Abstract

We investigate the highly incoherent regime of hole-doped 2d Mott-Hubbard insulators at moderately small doping and temperatures T>=0.1J, where J is the exchange coupling. Within an extended dynamical mean-field theory of the t-J model and a generalized non-crossing 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 both in the single-particle and the 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 doping.