Bidimensional nano-optomechanics and topological backaction in a non-conservative radiation force field

• Published in: Nature nanotechnology Vol. 9; no. 11; pp. 920 - 926
• Main Authors: Gloppe, A., Verlot, P., Dupont-Ferrier, E., Siria, A., Poncharal, P., Bachelier, G., Vincent, P., Arcizet, O.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-11-2014; Nature Publishing Group
• Subjects: 147/136; 639/624/400/1103; 639/766/1130/2800; 639/925/927/359; Dynamic tests; Dynamics; Joining; Materials Science; Nanostructure; Nanotechnology; Nanotechnology and Microengineering; Nanowires; Optics; Oscillators; Physics; Quantum Physics; Radiation; Scanning force microscopy; Signatures; Topology; France
• ISSN: 1748-3387; 1748-3395
• DOI: 10.1038/nnano.2014.189

Optomechanics, which explores the fundamental coupling between light and mechanical motion, has made important advances in manipulating macroscopic mechanical oscillators down to the quantum level. However, dynamical effects related to the vectorial nature of the optomechanical interaction remain to be investigated. Here we study a nanowire with subwavelength dimensions coupled strongly to a tightly focused beam of light, enabling an ultrasensitive readout of the nanoresonator dynamics. We determine experimentally the vectorial structure of the optomechanical interaction and demonstrate that a bidimensional dynamical backaction governs the nanowire dynamics. Moreover, the spatial topology of the optomechanical interaction is responsible for novel canonical signatures of strong coupling between mechanical modes, which leads to a topological instability that underlies the non-conservative nature of the optomechanical interaction. These results have a universal character and illustrate the increased sensitivity of nanomechanical devices towards spatially varying interactions, opening fundamental perspectives in nanomechanics, optomechanics, ultrasensitive scanning force microscopy and nano-optics.
A study of the coupling between a nanowire and a focused light beam allows determination of the vectorial structure of the optomechanical interaction, and demonstrates that bidimensional dynamical backaction governs the nanowire dynamics.