Chemistry Reference
In-Depth Information
10
μ
5
0
1.0
0.8
0.6
1.8
1.6
1.4
1.2
1.0
0.4
0.2
0.0
-0.2
-0.4
0.1
0.0
-0.1
-0.2
0123456789 0
N
(ML)
Fig. 4.19
The numerical results of surface energy and work functions from a quantum well model
calculations. Reproduced from [
53
]
4.6.3 Localized Surface Phonons and Electron-Phonon
Interaction
Electron-phonon coupling is an important factor that determines the superconduc-
tivity of a material. For a conventional superconductor such as Pb, the effective
electron-electron attraction necessary for the binding of cooper pairs is ultimately
governed by electron-phonon coupling [
56
]. The formation of QWS strongly modi-
fies the mechanical stability of the films, as reflected by the expansion and shrinkage
of interlayer spacing [
57
]. Both of the factors speak directly to the possibility of
modulating electron-phonon coupling and thus superconductivity of the Pb films.
Zhang et al. studied the interaction of electron-phonon coupling in Pb films
with different thickness by using the variable temperature ARPES spectra and
temperature-dependent PES [
58
]. The temperature-dependent PES for the 23 and
