Evidence for a multiple superconducting gap in MgB(2) from high-resolution photoemission spectroscopy.
We study the new binary intermetallic superconductor MgB(2) using high-resolution photoemission spectroscopy. The superconducting-state spectrum measured at 5.4 K shows a coherent peak with a shoulder structure, in sharp contrast to that expected from a simple isotropic-gap opening. The spectrum can be well reproduced using the weighted sum of two Dynes functions with the gap sizes of 1.7 and 5.6 meV. Temperature-dependent study shows that both gaps close at the bulk transition temperature. These results provide spectroscopic evidence for a multiple gap of MgB(2).
Tsuda
S
S
Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
Yokoya
T
T
Kiss
T
T
Takano
Y
Y
Togano
K
K
Kito
H
H
Ihara
H
H
Shin
S
S