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arXiv · 1701.02390

Dyadic Green's function formalism for photo-induced forces in tip-sample nanojunctions

Faezeh Tork Ladani·Eric O. Potma
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Abstract

A comprehensive theoretical analysis of photo-induced forces in an illuminated nanojunction, formed between an atomic force microscopy tip and a sample, is presented. The formalism is valid within the dipolar approximation and includes multiple scattering effects between the tip, sample and a planar substrate through a dyadic Green's function approach. This physically intuitive description allows a detailed look at the quantitative contribution of multiple scattering effects to the measured photo-induced force, effects that are typically unaccounted for in simpler analytical models. Our findings show that the presence of the planar substrate and anisotropy of the tip have a substantial effect on the magnitude and the spectral response of the photo-induced force exerted on the tip. Unlike previous models, our calculations predict photo-induced forces that are within range of experimentally measured values in photo-induced force microscopy (PiFM) experiments.

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Faezeh Tork Ladani, Eric O. Potma. 2017-01-09. Dyadic Green's function formalism for photo-induced forces in tip-sample nanojunctions. https://doi.org/10.1103/physrevb.95.205440

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