Absence of a loss of in-plane infrared spectral weight in the pseudogap regime of Bi(2)Sr(2)CaCu(2)O(8+delta).
The ab-plane reflectance of Bi(2)Sr(2)CaCu(2)O(8+delta) (Bi-2212) thin films was measured in the 30-25 000 cm(-1) range for one underdoped ( T(c) = 70 K), and one overdoped sample ( T(c) = 63 K) down to 10 K. We find similar behaviors in the temperature dependence of the normal-state infrared response of both samples. Above T(c), the effective spectral weight, obtained from the integrated conductivity, does not decrease when T decreases, so that no opening of an optical pseudogap is seen. We suggest that these are consequences of the pseudogap opening in the k = (0,pi) direction and of the in-plane infrared conductivity being mostly sensitive to the k = (pi,pi) direction.
Santander-Syro
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AF
Laboratoire de Physique du Solide, Ecole Supérieure de Physique et Chimie Industrielles de la Ville de Paris, CNRS UPR 5, 75231 Paris Cedex 5, France.
Lobo
R P S M
RP
Bontemps
N
N
Konstantinovic
Z
Z
Li
Z
Z
Raffy
H
H