Electron pockets and pseudogap asymmetry observed in the thermopower of underdoped cuprates

TL;DR

This paper models the thermopower in underdoped cuprates using the YRZ spin-liquid model, revealing how pseudogap asymmetry and electron pockets influence thermoelectric properties and match experimental observations.

Contribution

It introduces a detailed calculation of thermopower based on the YRZ model, highlighting the role of pseudogap asymmetry and electron pockets in underdoped cuprates.

Findings

Asymmetric pseudogap explains large thermopower magnitude and temperature dependence.

Evidence of electron pockets near pseudogap onset in experimental data.

Model reproduces key features of thermopower in underdoped cuprates.

Abstract

We calculate the diffusion thermoelectric power of high-Tc cuprates using the resonating-valence-bond spin-liquid model developed by Yang, Rice and Zhang (YRZ). In this model, reconstruction of the energy-momentum dispersion results in a pseudogap in the density of states that is heavily asymmetric about the Fermi level. The subsequent asymmetry in the spectral conductivity is found to account for the large magnitude and temperature dependence of the thermopower observed in underdoped cuprates. In addition we find evidence in experimental data for electron pockets in the Fermi surface, arising from a YRZ-like reconstruction, near the onset of the pseudogap in the slightly overdoped regime.