Quasiparticle spectral weights of Gutzwiller-projected high T_c superconductors

TL;DR

This paper investigates the effects of Gutzwiller projection on the electronic spectral functions in high-temperature superconductors, revealing preserved features, spectral weight reduction, and electron-hole asymmetry that influence the Fermi surface shape.

Contribution

It provides a detailed analysis of how Gutzwiller projection modifies spectral weights and Fermi surface properties in the t-J model's superconducting state, highlighting new asymmetries and renormalizations.

Findings

Spectral weight remains continuous around the quasiparticle node.

Projection causes a momentum-dependent reduction in spectral weight.

Electron-hole asymmetry leads to Fermi surface bending.

Abstract

We analyze the electronic Green's functions in the superconducting ground state of the t-J model using Gutzwiller-projected wave functions, and compare them to the conventional BCS form. Some of the properties of the BCS state are preserved by the projection: the total spectral weight is continuous around the quasiparticle node and approximately constant along the Fermi surface. On the other hand, the overall spectral weight is reduced by the projection with a momentum-dependent renormalization, and the projection produces electron-hole asymmetry in renormalization of the electron and hole spectral weights. The latter asymmetry leads to the bending of the effective Fermi surface which we define as the locus of equal electron and hole spectral weight.