Correlation-driven Lifshitz transition at the emergence of the pseudogap phase in the two-dimensional Hubbard model

TL;DR

This study reveals a correlation-driven Lifshitz transition linked to the emergence of the pseudogap phase in the two-dimensional Hubbard model, connecting Fermi surface topology changes with pseudogap phenomena relevant to cuprates.

Contribution

It uncovers a correlation-driven Lifshitz transition associated with the pseudogap phase, providing a theoretical explanation for experimental observations in cuprate superconductors.

Findings

Pseudogap phase becomes ground state at large interaction and small doping.

First-order transition from pseudogap to conventional metal involves a Fermi surface change.

Lifshitz transition is driven by electron correlations, not band structure.

Abstract

We study the relationship between the pseudogap and Fermi-surface topology in the two-dimensional Hubbard model by means of the cellular dynamical mean-field theory. We find two possible mean-field metallic solutions on a broad range of interaction, doping and frustration: a conventional renormalized metal and an unconventional pseudogap metal. At half-filling, the conventional metal is more stable and displays an interaction-driven Mott metal-insulator transition. However, for large interaction and small doping, region that is relevant for cuprates, the pseudogap phase becomes the ground state. By increasing doping, we show that a first-order transition from the pseudogap to the conventional metal is tight to a change of the Fermi surface from hole to electron like, unveiling a correlation-driven mechanism for a Lifshitz transition. This explains the puzzling link between pseudogap phase and Fermi surface topology which has been pointed out in recent experiments.