25 research outputs found
Granular Effect on Electron Conduction in Discontinuous Metal Films
We reanalyze the seminal work by Dolan and Osheroff [Phys. Rev. Lett.
, 721 (1979)] which reported anomalous low-temperature conduction
of high-resistivity thin-film metal strips. We argue that the observed
logarithmic increase of resistance with decreasing temperature in their
3-nm-thick Au-Pd strips be ascribed to the granularity effect on electron
conduction in discontinuous metal films. This reanalysis is further supported
by our measurements on conducting Pb(SiO) nanogranular films,
where is the volume fraction of Pb.Comment: 7 pages, 2 figure
Two-Channel Kondo Effects in Al/AlO/Sc Planar Tunnel Junctions
We have measured the differential conductances in several
Al/AlO/Sc planar tunnel junctions between 2 and 35 K. As the temperature
decreases to 16 K, the zero-bias conductance crosses over from
a standard ln dependence to a novel dependence.
Correspondingly, the finite bias conductance reveals a two-channel
Kondo scaling behavior between 4 and 16 K. The observed two-channel
Kondo physics is ascribed to originating from a few localized spin- Sc
atoms situated slightly inside the AlO/Sc interface.Comment: 4 pages, 3 figures. Phys. Rev. B (accepted