We have measured the differential conductances G (V,T) in several Al/ AlOx /Sc planar tunnel junctions between 2 and 35 K. As the temperature decreases to ∼16̃K, the zero-bias conductance G (0,T) crosses over from a standard -lnT dependence to a novel -T dependence. Correspondingly, the finite bias conductance G (V,T) 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- 1 2 Sc atoms situated slightly inside the AlOx /Sc interface.
|Number of pages||4|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 5 Jan 2009|