Parametric resonance based scanning probe microscopy

M. Moreno-Moreno, Laboratorio de Nuevas Microscopías, Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid
Arvind Raman, Birck Nanotechnology Center and School of Mechanical Engineering, Purdue University
J. Gomez-Herrero, Laboratorio de Nuevas Microscopías, Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid
R. Reifenberger, Birck Nanotechnology Center and Department of Physics, Purdue University

Abstract

We propose a mode of dynamic scanning probe microscopy based on parametric resonance for highly sensitive nanoscale imaging and force spectroscopy. In this mode the microcantilever probe is excited by means of a closed-loop electronic circuit that modulates the microcantilever stiffness at a frequency close to twice its natural resonance frequency. Under ambient conditions this parametric pumping leads to self-sustained oscillations in a narrow frequency bandwidth thereby resulting in exquisitely sharp, controllable, and non-Lorentzian resonance peaks. We discuss and demonstrate the potential of imaging and force spectroscopy using this mode.