Pseudogap-induced coexistence of Fermi arcs and Fermi pockets in cuprate superconductors

TL;DR

This paper explains the coexistence of Fermi arcs and pockets in cuprate superconductors' pseudogap phase through a model showing pseudogap-induced band splitting and spectral weight redistribution, aligning with experimental observations.

Contribution

It introduces a theoretical framework based on the t-J model that accounts for the coexistence of Fermi arcs and pockets by considering pseudogap effects and predicts specific spectral features.

Findings

Fermi arcs and pockets coexist due to pseudogap-induced band splitting.

Spectral weight is gapped around antinodal regions, leaving disconnected segments.

The model's dispersion matches experimental data qualitatively.

Abstract

One of the most intriguing puzzle is why there is a coexistence of Fermi arcs and Fermi pockets in the pseudogap phase of cuprate superconductors? This puzzle is calling for an explanation. Based on the t-J model in the fermion-spin representation, the coexistence of the Fermi arcs and Fermi pockets in cuprate superconductors is studied by taking into account the pseudogap effect. It is shown that the pseudogap induces an energy band splitting, and then the poles of the electron Green's function at zero energy form two contours in momentum space, however, the electron spectral weight on these two contours around the antinodal region is gapped out by the pseudogap, leaving behind the low-energy electron spectral weight only located at the disconnected segments around the nodal region. In particular, the tips of these disconnected segments converge on the hot spots to form the closed Fermi pockets, generating a coexistence of the Fermi arcs and Fermi pockets. Moreover, the single-particle coherent weight is directly related to the pseudogap, and grows linearly with doping. The calculated result of the overall dispersion of the electron excitations is in qualitative agreement with the experimental data. The theory also predicts that the pseudogap-induced peak-dip-hump structure in the electron spectrum is absent from the hot-spot directions.