Steurer, Wolfram and Repp, Jascha and Gross, Leo and Meyer, Gerhard (2018) Damping by sequentially tunneling electrons. SURFACE SCIENCE, 678. pp. 112-117. ISSN 0039-6028, 1879-2758
Full text not available from this repository. (Request a copy)Abstract
Sequential tunneling of electrons through a single chlorine vacancy on a multilayer NaCl film on Cu(100) in the junction of a non-contact atomic force microscope with a conductive tip can lead to a negative damping of the cantilever. The characteristic features in the damping signal as a function of NaCl-layer thickness, tip position and tip-sample bias can be explained in a simple rate-equation model for the sequential tunneling process through the double-barrier tunnel junction. The first barrier results from the vacuum gap between tip and vacancy and its tunneling rate is tuned by the tip position and the applied bias. The second barrier results from the NaCl film and its tunneling rate is governed by the film's thickness. The current-induced damping is strongest if the two tunneling rates through each of the barriers individually are both comparable to the cantilever's oscillation frequency. The damping signal can be employed for detecting subfemtoampere tunneling currents and furthermore, maps of the damping signal can be used to inspect the mesoscopic tip shape. The observed and described current-induced damping should be a common phenomenon in non-contact atomic force microscopy for double-barrier tunnel junction geometries. (C) 2018 Published by Elsevier B.V.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | FORCE MICROSCOPY; QUANTUM DOTS; GRAPHENE; MOTION; Atomic force microscopy; Scanning tunneling microscopy; Damping; Double-barrier tunnel junction; Thin insulating films; Atomic defects |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Experimental and Applied Physics > Chair Professor Giessibl > Group Jascha Repp |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 04 Oct 2019 08:37 |
| Last Modified: | 04 Oct 2019 08:37 |
| URI: | https://pred.uni-regensburg.de/id/eprint/13407 |
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