Differential Sum Rule for the Relaxation Rate in the Cuprates
Abstract
Motivated by recent experiments by Basov et al., we study the differential sum rule for the effective scattering rate 1/τ(ω). We show that, in a dirty BCS superconductor, the area under 1/τ(ω) does not change between the normal and the superconducting states. For magnetically mediated pairing, a similar result holds between T<T_{c} and T>=T_{c}, while, in the pseudogap phase, 1/τ(ω) is just suppressed compared to 1/τ(ω) in the normal state. We argue that this violation of the differential sum rule in the pseudogap phase is due to the absence of the feedback effects from the pairing.
 Publication:

Physical Review Letters
 Pub Date:
 May 2002
 DOI:
 10.1103/PhysRevLett.88.217001
 arXiv:
 arXiv:condmat/0112085
 Bibcode:
 2002PhRvL..88u7001A
 Keywords:

 Condensed Matter  Superconductivity;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 4 pages, 5 figures