Fermi-surface Reconstruction in the Repulsive Fermi-Hubbard Model

TL;DR

This paper investigates how the Fermi surface in the repulsive Fermi-Hubbard model reconstructs from a large Fermi surface to a smaller one as the Mott insulator is approached, revealing a continuous transition violating Luttinger's theorem.

Contribution

The study demonstrates a continuous Fermi surface reconstruction in the Fermi-Hubbard model, identifying a non-Fermi liquid phase with a Luttinger count violation near the Mott transition.

Findings

Fermi surface transitions from large to smaller volume near Mott insulator

Identification of a Luttinger Breaking phase with fewer electrons

Continuous phase transition without symmetry breaking

Abstract

One of the fundamental questions about the high temperature cuprate superconductors is the size of the Fermi surface (FS) underlying the superconducting state. By analyzing the single particle spectral function for the Fermi Hubbard model as a function of repulsion $U$ and chemical potential $\mu$, we find that the Fermi surface in the normal state reconstructs from a large Fermi surface matching the Luttinger volume as expected in a Fermi liquid, to a Fermi surface that encloses fewer electrons that we dub the "Luttinger Breaking" (LB) phase, as the Mott insulator is approached. This transition into a non-Fermi liquid phase that violates the Luttinger count, is a continuous phase transition at a critical density in the absence of any other broken symmetry. We obtain the Fermi surface contour from the spectral weight $A_{\vec{k}}(\omega=0)$ and from an analysis of the poles and zeros of the retarded Green's function $G_{\vec{k}}^{ret}(E=0)$, calculated using determinantal quantum Monte Carlo and analytic continuation methods.We discuss our numerical results in connection with experiments on Hall measurements, scanning tunneling spectroscopy and angle resolved photoemission spectroscopy.