Bogoliubov Quasiparticle Excitations in the Two-Dimensional t-J Model

TL;DR

This study uses a numerical technique to show that low-energy excitations in the 2D t-J model resemble dressed Bogoliubov quasiparticles with d-wave pairing, demonstrating a superconducting gap in spectral functions.

Contribution

It introduces a numerical method to calculate anomalous Green's functions, revealing d-wave superconductivity and quasiparticle behavior in the 2D t-J model.

Findings

Low-lying excitations are described by dressed Bogoliubov quasiparticles.

Superconducting gap appears in spectral functions.

D-wave pairing dominates in the model.

Abstract

Using a proposed numerical technique for calculating anomalous Green's functions characteristic of superconductivity, we show that the low-lying excitations in a wide parameter and doping region of the two-dimensional $t$$-$$J$ model are well described by the picture of dressed Bogoliubov quasiparticles in the BCS pairing theory. The pairing occurs predominantly in $d_{x^2-y^2}$-wave channel and the energy gap has a size $\Delta_d$$\simeq$$0.15J$$-0.27J$ between quarter and half fillings. Opening of the superconducting gap in the photoemission and inverse-photoemission spectrum is demonstrated.