Quasiparticle Dispersion of the 2D Hubbard Model: From an Insulator to a Metal

TL;DR

This paper uses Quantum Monte Carlo results to study how the spectral weight and quasiparticle dispersion in the 2D Hubbard model evolve from insulator to metal, highlighting the role of antiferromagnetic correlations.

Contribution

It provides a detailed analysis of the spectral evolution in the 2D Hubbard model from insulating to metallic phases based on Quantum Monte Carlo data, connecting it to experimental observations.

Findings

Spectral weight shows doping-independent features similar to cuprates.

A narrow quasiparticle-like band of width ~J is observed.

Evolution driven by doping-dependent antiferromagnetic correlations.

Abstract

On the basis of Quantum-Monte-Carlo results the evolution of the spectral weight $A(\vec k, \omega)$ of the two-dimensional Hubbard model is studied from insulating to metallic behavior. As observed in recent photoemission experiments for cuprates, the electronic excitations display essentially doping-independent features: a quasiparticle-like dispersive narrow band of width of the order of the exchange interaction $J$ and a broad valence- and conduction-band background. The continuous evolution is traced back to one and the same many-body origin: the doping-dependent antiferromagnetic spin-spin correlation.