Virtual resonance and frequency diference generation by Van der Walls interaction

Journal Article · Sat Jan 01 00:00:00 EST 2011 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.106.180801· OSTI ID:1081654

Tetard, Laurene ^[1]; Passian, Ali ^[2]; Eslami, S ^[3]; Jalili, N ^[3]; Thundat, Thomas George ^[2]

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1. University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)
2. ORNL
3. Clemson University

The ability to explore the interior of materials for presence of inhomogeneities was recently demon- strated by mode synthesizing atomic force microscopy [Tetard et al. Nature Nanotechnology (2010)]. However, the underlying mechanism of signal and image formation remain unexplored and not fully understood. Proposing a semi-empirical nonlinear force, we show that di erence frequency gener- ation, regarded as the simplest synthesized subsurface probe, occurs optimally when the force is tuned to Van der Waals form. From a parametric study in the probe-sample excitation plane, we show that the predicted behavior of the generated di erence-frequency oscillation amplitude agrees well with experimental measurements. We then introduce the concept of virtual resonance to show that probe oscillations at the generated di erence frequency can e ciently be enhanced.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1081654
• Journal Information: Physical Review Letters, Vol. 106, Issue 18; ISSN 0031--9007
• Country of Publication: United States
• Language: English