Kondo effect in electromigrated gold break junctions.
We present gate-dependent transport measurements of Kondo impurities in bare gold break junctions, generated with high yield using an electromigration process that is actively controlled. Thirty percent of measured devices show zero-bias conductance peaks. Temperature dependence suggests Kondo temperatures approximately 7 K. The peak splitting in magnetic field is consistent with theoretical predictions for g = 2, though in many devices the splitting is offset from 2g mu(B)B by a fixed energy. The Kondo resonances observed here may be due to atomic-scale metallic grains formed during electromigration.
Houck
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AA
Center for Bits and Atoms and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Labaziewicz
J
J
Chan
E K
EK
Folk
J A
JA
Chuang
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IL