Coherent spectral weight of Gutzwiller-projected superconductors

TL;DR

This paper investigates the spectral properties of Gutzwiller-projected superconductors in the t-J model, revealing preserved features of BCS states and new momentum-dependent spectral weight renormalizations.

Contribution

It provides a detailed analysis of how Gutzwiller projection affects spectral weight distribution and Fermi surface properties in superconducting states.

Findings

Spectral weight remains continuous around the quasiparticle node.

Projection causes a momentum-dependent reduction in spectral weight.

Electron-hole asymmetry leads to bending of the effective Fermi surface.

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.