Virtual Resonance and Frequency Difference Generation by van der Waals Interaction

L. Tetard, A. Passian, S. Eslami, N. Jalili, R. H. Farahi, and T. Thundat

Phys. Rev. Lett. 106, 180801 – Published 6 May 2011

Abstract

The ability to explore the interior of materials for the presence of inhomogeneities was recently demonstrated by mode synthesizing atomic force microscopy [L. Tetard, A. Passian, and T. Thundat, Nature Nanotech. 5, 105 (2009).]. Proposing a semiempirical nonlinear force, we show that difference frequency $ω_{-}$ generation, regarded as the simplest synthesized mode, occurs optimally when the force is tuned to van der Waals form. From a parametric study of the probe-sample excitation, we show that the predicted $ω_{-}$ oscillation agrees well with experiments. We then introduce the concept of virtual resonance to show that probe oscillations at $ω_{-}$ can efficiently be enhanced.

Received 2 June 2010

DOI:https://doi.org/10.1103/PhysRevLett.106.180801

Authors & Affiliations

L. Tetard^1,2, A. Passian^1,2,*, S. Eslami³, N. Jalili³, R. H. Farahi¹, and T. Thundat^1,2

¹Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6123, USA
²Department of Physics, University of Tennessee, Knoxville, Tennessee 37996, USA
³Department of Mechanical Engineering, Northeastern University, Boston, Massachusetts 02115, USA