Quantum Mirages in Scanning Tunneling Spectroscopy of Kondo Adsorbates: Vibrational Signatures

Published

December 1, 2003

Author(s)

John William Gadzuk, M Plihal

Abstract

Scanning tunneling microscopy/spectroscopy on Kondo systems consisting of magnetic atoms adsorbed upon non-magnetic metal surfaces has demonstrated the ability of suitable two-dimensional nanostructures (such as quantum corrals) to influence the surface electron transport that is part of the total STM process. In a well known paradigm, an elliptical arrangement of Co atoms adsorbed on Cu(111) gives rise to an apparent enhanced electronic communication between points on the surface which are near the two elliptical foci. The question addressed here is whether a similar imaging/mirage effect can be expected and does it have the potential for being interesting and/or useful when focused tunneling processes also involve the vibrational modes of the adsorbate. Theory for the total process of tip-to-corral state tunneling, focus-to-focus transport via (corral) surface states [following Agam and Schiller], and adsorbate resonance scattering has been developed within a localized polaron framework for incorporation of vibrational effects. Calculated lineshapes illustrate the potential utility of tunneling spectroscopy for obtaining unique, atomic scale understanding of the role of the elliptical nanostructure size, shape, and chemical composition (as manifest in resonance characteristics) on both surface transport processes and also on the measurement methodologies required to probe such systems. This presents unusual challenges since all the characteristic energies [resonance position and width, vibrational, relaxation, and quantum corral] are of comparable magnitude in realistic experimental STM Kondo systems.

Citation

Physical Review B (Condensed Matter and Materials Physics)

Volume

68

Issue

No. 23

Pub Type

Journals

Keywords

kondo systems, nanostructures, quantum corrals, STM, surface vibrational spectroscopy

Citation

, J. and Plihal, M. (2003), Quantum Mirages in Scanning Tunneling Spectroscopy of Kondo Adsorbates: Vibrational Signatures, Physical Review B (Condensed Matter and Materials Physics) (Accessed December 5, 2024)