Condensation Energy and Spectral Functions in High Temperature Superconductors

TL;DR

This paper explores how the energy difference between normal and superconducting states in high-Tc cuprates relates to spectral functions derived from ARPES data, emphasizing the role of spectral shape changes below Tc.

Contribution

It demonstrates the connection between ARPES spectral functions and condensation energy, analyzing the energy contributions in high-temperature superconductors with a focus on the normal state's non-Fermi liquid behavior.

Findings

Spectral shape changes below Tc are linked to the condensation energy.

Normal state spectral functions vary with doping, affecting superconducting transition nature.

ARPEs data can inform on whether kinetic or potential energy drives superconductivity.

Abstract

If high temperature cuprate superconductivity is due to electronic correlations, then the energy difference between the normal and superconducting states can be expressed in terms of the occupied part of the single particle spectral function. The latter can, in principle, be determined from angle resolved photoemission (ARPES) data. As a consequence, the energy gain driving the development of the superconducting state is intimately related to the dramatic changes in the photoemission lineshape when going below Tc. These points are illustrated in the context of the "mode" model used to fit ARPES data in the normal and superconducting states, where the question of kinetic energy versus potential energy driven superconductivity is explored in detail. We use our findings to comment on the relation of ARPES data to the condensation energy, and to various other experimental data. In particular, our results suggest that the nature of the superconducting transition is strongly related to how anomalous (non Fermi liquid like) the normal state spectral function is, and as such, is dependent upon the doping level.