Temperature-dependent localized excitations of doped carriers in superconducting diamond.
Laser-excited photoemission spectroscopy is used to show that the doped carriers in metallic or superconducting diamond couple strongly to the lattice via high-energy (approximately 150 meV) optical phonons, with direct observations of localized Franck-Condon multiphonon sidebands appearing as Fermi-edge replicas. It exhibits a temperature-dependent spectral weight transfer from higher to lower energy sidebands and zero-phonon Fermi-edge states. The quantified coupling strength shows a systematic increase on lowering temperature, implicating its relation to the normal state transport and superconductivity.
Ishizaka
K
K
Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
Eguchi
R
R
Tsuda
S
S
Chainani
A
A
Yokoya
T
T
Kiss
T
T
Shimojima
T
T
Togashi
T
T
Watanabe
S
S
Chen
C-T
CT
Takano
Y
Y
Nagao
M
M
Sakaguchi
I
I
Takenouchi
T
T
Kawarada
H
H
Shin
S
S