Article,
Phenomenology of the low-energy spectral function in high-$Tc$ superconductors
Phys. Rev. B, 57 (18): R11093--R11096 (May 1998)
DOI: 10.1103/PhysRevB.57.R11093
Abstract
We introduce a simple phenomenological form for the self-energy which
allows us to extract important information from angle-resolved photoemission
data on the high-Tc superconductor Bi2Sr2CaCu2O8 for binding energies
of order the spectral gap. First, we find a rapid suppression of
the single particle scattering rate below Tc for all doping levels.
Second, we find that in the overdoped materials the gap Δ at all
k points on the Fermi surface has significant temperature dependence
and vanishes near Tc. In contrast, in the underdoped samples such
behavior is found only at k points close to the diagonal. Near (π,0),
Δ is essentially T independent in the underdoped samples. The filling-in
of the pseudogap with increasing T is described by a broadening proportional
to T-Tc, which is naturally explained by pairing correlations above
Tc.
