Within a spectral function A(k,ω) interpretation of angle-resolved photoemission (ARPES), the intensity obeys the sum rule dω fωA(k,ω)=nk, where f is the Fermi function and nk the momentum distribution. We show the usefulness of this sum rule for analyzing ARPES data. The integrated intensity in Bi2Sr2CaCu2O8 at kF is independent of temperature even though the spectrum is strongly T dependent. We also demonstrate the possibility of measuring nk using ARPES for YBa2Cu4O8.
ASJC Scopus subject areas
- General Physics and Astronomy