38,778 research outputs found
Doping and energy evolution of spin dynamics in the electron-doped cuprate superconductor PrLaCeCuO
The doping and energy evolution of the magnetic excitations of the
electron-doped cuprate superconductor PrLaCeCuO
in the superconducting state is studied based on the kinetic energy driven
superconducting mechanism. It is shown that there is a broad commensurate
scattering peak at low energy, then the resonance energy is located among this
low energy commensurate scattering range. This low energy commensurate
scattering disperses outward into a continuous ring-like incommensurate
scattering at high energy. The theory also predicts a dome shaped doping
dependent resonance energy.Comment: 8 pages, 4 figures, added discussions, replotted figures, and updated
references, accepted for publication in Phys. Rev.
Quantum size effect on adatom surface diffusion
Journal ArticleUsing scanning tunneling microscopy, we demonstrate that the nucleation density of Fe islands on the surface of nanoscale Pb films oscillates with the film thickness, providing a direct manifestation of the quantum size effect on surface diffusion. The Fe adatom diffusion barriers were derived to be 204 ± 5 and 187 ± 5 meV on a 21 and 26 monolayer (ML) Pb film, respectively, by matching the kinetic Monte Carlo simulations to the experimental island densities. The effect is further illustrated by the growth of Fe islands on wedged Pb films, where the Fe island density is consistently higher on the odd-layer films than on the even-layer films in the thickness range of 11 to 15 ML
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