One-particle spectral properties of the t-J-$V$ model on the triangular lattice near charge order

TL;DR

This paper investigates the spectral properties of the t-J-V model on a triangular lattice near charge order, revealing how charge fluctuations affect quasiparticles and potentially relate to cobaltate materials.

Contribution

It provides a beyond mean field analysis of the t-J-V model, highlighting the impact of charge fluctuations on spectral functions near charge ordering.

Findings

Charge fluctuations become soft near charge order.

Incoherent one-particle excitations emerge close to the charge ordered phase.

Implications for cobaltate materials are discussed.

Abstract

We study the t-J-$V$ model beyond mean field level at finite doping on the triangular lattice. The Coulomb repulsion $V$ between nearest neighbors brings the system to a charge ordered state for $V$ larger than a critical value $V_c$. One-particle spectral properties as self-energy, spectral functions and the quasiparticle weight are studied near and far from the charge ordered phase. When the system approaches the charge ordered state, charge fluctuations become soft and they strongly influence the system leading to incoherent one-particle excitations. Possible implications for cobaltates are given.