Local spectroscopy of a kondo impurity: Co on Au(111)

Journal Article · Sun Jul 15 04:00:00 EDT 2001 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevB.64.165412· OSTI ID:917034

Madhavan, V; Chen, W; Jamneala, T; Crommie, M F; Wingreen, N S

We present a detailed study of the local electronic properties of the Kondo system formed from cobalt adatoms deposited onto Au(111) at a temperature of 6.6 K. Cryogenic scanning-tunneling spectroscopy was used to observe impurity-induced resonances at the Fermi energy and at the Au(111) surface-state band edge. The line shape of the Fermi-energy resonance, identified as a Kondo resonance, is observed to vary with lateral position from the impurity center and with impurity binding position on the reconstructed Au(111) surface. Little vertical dependence is seen in the resonance line shape for positions above the center of the impurity. Interaction effects between Kondo impurities are observed to remain small as cobalt coverage is increased up to 1 ML on the gold surface. The Kondo resonance is shown theoretically to be a member of a general class of Fano resonances arising from the interaction of a discrete impurity state with a conduction-electron continuum. The asymmetric line shape of the resonance thus reflects quantum interference between the d orbital and continuum conduction electron channels, as well as their coupling to the STM tip.

• Research Organization: Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director, Office of Science
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 917034
• Report Number(s): LBNL--49963
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 25 Vol. 87; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COBALT
ELECTRONIC STRUCTURE
FERMI LEVEL
GOLD
IMPURITIES
KONDO EFFECT
RESONANCE
SUBSTRATES