Interaction induced Fermi-surface renormalization in the $t_1{-}t_2$ Hubbard model close to the Mott-Hubbard transition

TL;DR

This study uses variational Monte Carlo methods to analyze how the Fermi surface in a one-dimensional $t_1{-}t_2$ Hubbard model evolves near the Mott-Hubbard transition, revealing a perfect nesting at the transition and a first-order reorganization in the conducting state.

Contribution

It provides a detailed variational Monte Carlo analysis of Fermi-surface renormalization and magnetic properties near the Mott-Hubbard transition in a 1D Hubbard model, including the effects of interactions.

Findings

Fermi surface renormalizes to perfect nesting at the Mott-Hubbard transition.

First-order reorganization of the Fermi surface occurs when crossing into the conducting state.

Magnetic properties evolve across the transition, indicating changes in magnetic correlations.

Abstract

We investigate the nature of the interaction-driven Mott-Hubbard transition of the half-filled $t_1{-}t_2$ Hubbard model in one dimension, using a full-fledged variational Monte Carlo approach including a distance-dependent Jastrow factor and backflow correlations. We present data for the evolution of the magnetic properties across the Mott-Hubbard transition and on the commensurate to incommensurate transition in the insulating state. Analyzing renormalized excitation spectra, we find that the Fermi surface renormalizes to perfect nesting right at the Mott-Hubbard transition in the insulating state, with a first-order reorganization when crossing into the conducting state.