title: Kondo effect in electromigrated gold break junctions.
abstract: 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.
authors.affiliation: Center for Bits and Atoms and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Houck
authors.forename: J
authors.initials: J
authors.lastname: Labaziewicz
authors.forename: E K
authors.initials: EK
authors.lastname: Chan
authors.forename: J A
authors.initials: JA
authors.lastname: Folk
authors.forename: I L
authors.initials: IL
authors.lastname: Chuang