Enhanced superconducting gaps in the trilayer high-temperature Bi2Sr2Ca2Cu3O(10+δ) cuprate superconductor.
We report the first observation of the multilayer band splitting in the optimally doped trilayer cuprate Bi2Sr2Ca2Cu3O(10+δ) (Bi2223) by angle-resolved photoemission spectroscopy. The observed energy bands and Fermi surfaces are originated from the outer and inner CuO2 planes (OP and IP). The OP band is overdoped with a large d-wave gap around the node of Δ0∼43  meV while the IP is underdoped with an even large gap of Δ0∼60  meV. These energy gaps are much larger than those for the same doping level of the double-layer cuprates, which leads to the large Tc in Bi2223. We propose possible origins of the large superconducting gaps for the OP and IP: (1) minimal influence of out-of-plane disorder and a proximity effect and (2) interlayer tunneling of Cooper pairs between the OP and IP.
Ideta
S
S
Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
Takashima
K
K
Hashimoto
M
M
Yoshida
T
T
Fujimori
A
A
Anzai
H
H
Fujita
T
T
Nakashima
Y
Y
Ino
A
A
Arita
M
M
Namatame
H
H
Taniguchi
M
M
Ono
K
K
Kubota
M
M
Lu
D H
DH
Shen
Z-X
ZX
Kojima
K M
KM
Uchida
S
S