Signatures of a momentum independent pseudogap in the electronic density of states and Raman spectroscopy of the underdoped cuprates

Abstract

We propose a hybridization phenomenology to describe the pseudogap state of underdoped cuprates. We show how a momentum independent pseudogap opens asymmetrically from the Fermi-surface but symmetric to the zeroes of the hybridized bonding dispersion, which results in false d-wave characteristics of the pseudogap at the Fermi level. By comparing against a d-wave form factor we illustrate the difficulty in identifying a momentum independent order in momentum averaged quantities such as the electronic Raman response. We identify a suppression in the single-particle density of states which produces a hump feature which should be observable experimentally in tunnelling ${\rm d}I/{\rm d}V$ spectra and distinguishes the s-wave and d-wave ordering scenarios.

Keywords

• pseudogap
• cuprates
• s-wave
• yrz
• phenomenology
• 74.72.Kf