Photoemission Spectra in t-J Ladders with Two Legs

TL;DR

This paper calculates photoemission spectra for the two-leg t-J ladder model, revealing features related to antiferromagnetic correlations and d-wave pairing that could be observed experimentally.

Contribution

It provides the first detailed calculation of photoemission spectra in the isotropic two-leg t-J ladder at various doping levels using exact diagonalization.

Findings

Sharp low-energy features near half-filling due to antiferromagnetic correlations

Spectral weight appears near the Fermi momentum with d-wave pairing

Results are relevant for angle-resolved photoemission experiments

Abstract

Photoemission spectra for the isotropic two-leg t-J ladder are calculated at various hole-doping levels using exact diagonalization techniques. Low-energy sharp features caused by short-range antiferromagnetic correlations are observed at finite doping levels close to half-filling, above the naive Fermi momentum. These features should be observable in angle-resolved photoemission experiments. In addition, the formation of a d-wave pairing condensate as the ratio J/t is increased leads to dynamically generated spectral weight for momenta close to $k_F$ where the $d_{x^2-y^2 }$-order parameter is large.