Photoemission spectroscopy of the strong-coupling superconducting transitions in lead and niobium
We study the changes in the electronic structure associated with low- T(c) strong-coupling superconducting transitions in Pb and Nb using ultrahigh-resolution (2.3 meV) temperature-dependent (5.3-12.0 K) photoemission spectroscopy. We observe peaks in the density of states on entering the superconducting-phase accompanying gap formation and spectacular redistribution of spectral weight at low energy scales as a function of temperature. The well-known peak-dip feature of the high- T(c) cuprates is seen in Pb, making it a characteristic of strong-coupling superconductivity.
Chainani
A
Institute for Plasma Research, Bhat, Gandhinagar-382 428, India and Institute for Solid State Physics (ISSP), University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
Yokoya
T
Kiss
T
Shin
S