Effects of a particle-hole asymmetric pseudogap on Bogoliubov quasiparticles

TL;DR

This paper investigates how a particle-hole asymmetric pseudogap affects Bogoliubov quasiparticles in underdoped cuprates, revealing additional spectral features and providing insights into the pseudogap's temperature evolution through ARPES data.

Contribution

It demonstrates the impact of a particle-hole asymmetric pseudogap on quasiparticle spectra and links the pseudogap's gradual opening to experimental ARPES observations using the RVB model.

Findings

Additional Bogoliubov peaks appear at positive and negative energies.

Spectral density broadens with decreasing temperature in the superconducting state.

Pseudogap opens gradually below T* as supported by ARPES data.

Abstract

We show that in the presence of a pseudogap, the spectral function in the superconducting state of the underdoped cuprates exhibits additional Bogoliubov quasiparticle peaks at both positive and negative energy which are revealed by the particle-hole asymmetry of the pseudogapped energy bands. This provides direct information on the unoccupied band via measurement of the occupied states. When sufficiently close, these Bogoliubov peaks will appear to merge with existing peaks leading to the anomalous observation, seen in experiment, that the carrier spectral density broadens with reduced temperature in the superconducting state. Using the resonating valence bond (RVB) spin liquid model in conjunction with recent angle-resolved photoemission spectroscopy (ARPES) data allows for an empirical determination of the temperature dependence of the pseudogap suggesting that it opens only very gradually below the pseudogap onset temperature $T^*$.