Optical sum in Nearly Antiferromagnetic Fermi Liquid Model

TL;DR

This paper calculates the optical sum and kinetic energy in a Nearly Antiferromagnetic Fermi Liquid model, showing how interactions significantly alter electronic properties relevant to high-temperature superconductors.

Contribution

It provides a detailed computation of optical sum and kinetic energy considering spin fluctuation interactions, advancing understanding of electronic behavior in high-Tc cuprates.

Findings

Interactions significantly affect optical sum and kinetic energy.

Independent electron models are insufficient to describe these properties.

Both normal and superconducting states show temperature-dependent changes.

Abstract

We calculate the optical sum (OS) and the kinetic energy (KE) for a tight binding band in the Nearly Antiferromagnetic Fermi Liquid (NAFFL) model which has had some success in describing the electronic structure of the high $T_c$ cuprates. The interactions among electrons due to the exchange of spin fluctuations profoundly change the probability of occupation $(n_{{\bf k},\sigma})$ of states of momentum {\bf k} and spin $\sigma$ which is the central quantity in the calculations of OS and KE. Normal and superconducting states are considered as a function of temperature. Both integrals are found to depend importantly on interactions and an independent electron model is inadequate.