Temperature-induced spectral weight transfer in Bi_2Sr_2CaCu_2O_{8+delta}: a conventional view

TL;DR

This paper explains temperature-induced spectral weight transfer in Bi_2Sr_2CaCu_2O_{8+delta} using conventional sum rule principles, contrasting recent observations of anomalous behavior.

Contribution

It demonstrates that the integrated spectral weight remains nearly constant with temperature, supporting the conventional sum rule interpretation despite spectral lineshape changes.

Findings

Integrated spectral weight shows minimal variation with temperature.

Spectral lineshape changes do not imply spectral weight transfer.

Results align with the sum rule of angle-resolved photoemission.

Abstract

In contrast with the recent photoemission observations by Shen et al. of anomalous temperature-induced momentum-dependent spectral weight transfer in Bi_2Sr_2CaCu_2O_{8+delta}, we find that in the same material, in spite of the unusual spectral lineshape change between superconducting and normal states, the integrated spectral weight displays minimum variation as a function of temperature, which is in agreement with the sum rule of angle-resolved photoemission: the integrated spectral weight is proportional to the momentum density, n(k).