Pseudogap induced by short-range spin correlations in a doped Mott insulator

TL;DR

This paper investigates how short-range spin correlations induce a pseudogap in a doped Mott insulator, revealing a strong-coupling mechanism linked to additional bands and momentum-dependent spectral weight suppression.

Contribution

It demonstrates that short-range spin correlations create additional bands and cause a pseudogap in the spectral function of a doped Mott insulator, highlighting a strong-coupling origin.

Findings

Short-range spin correlations generate additional spectral bands.

Tiny doping causes Fermi energy to jump to these bands.

Pseudogap linked to these bands and momentum-dependent spectral suppression.

Abstract

We study the evolution of a Mott-Hubbard insulator into a correlated metal upon doping in the two-dimensional Hubbard model using the Cellular Dynamical Mean Field Theory. Short-range spin correlations create two additional bands apart from the familiar Hubbard bands in the spectral function. Even a tiny doping into this insulator causes a jump of the Fermi energy to one of these additional bands and an immediate momentum dependent suppression of the spectral weight at this Fermi energy. The pseudogap is closely tied to the existence of these bands. This suggests a strong-coupling mechanism that arises from short-range spin correlations and large scattering rates for the pseudogap phenomenon seen in several cuprates.