title: Bidimensional nano-optomechanics and topological backaction in a non-conservative radiation force field.
abstract: 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.
authors.affiliation: Institut Néel, Université Grenoble Alpes - CNRS:UPR2940, Grenoble 38042, France.
authors.forename: A
authors.initials: A
authors.lastname: Gloppe
authors.affiliation: Institut Néel, Université Grenoble Alpes - CNRS:UPR2940, Grenoble 38042, France.
authors.forename: P
authors.initials: P
authors.lastname: Verlot
authors.affiliation: Institut Néel, Université Grenoble Alpes - CNRS:UPR2940, Grenoble 38042, France.
authors.forename: E
authors.initials: E
authors.lastname: Dupont-Ferrier
authors.affiliation: Institut Lumière Matière, UMR5306, CNRS - Université Claude Bernard Lyon 1, Villeurbanne 69622, France.
authors.forename: A
authors.initials: A
authors.lastname: Siria
authors.affiliation: Institut Lumière Matière, UMR5306, CNRS - Université Claude Bernard Lyon 1, Villeurbanne 69622, France.
authors.forename: P
authors.initials: P
authors.lastname: Poncharal
authors.affiliation: Institut Néel, Université Grenoble Alpes - CNRS:UPR2940, Grenoble 38042, France.
authors.forename: G
authors.initials: G
authors.lastname: Bachelier
authors.affiliation: Institut Lumière Matière, UMR5306, CNRS - Université Claude Bernard Lyon 1, Villeurbanne 69622, France.
authors.forename: P
authors.initials: P
authors.lastname: Vincent
authors.affiliation: Institut Néel, Université Grenoble Alpes - CNRS:UPR2940, Grenoble 38042, France.
authors.forename: O
authors.initials: O
authors.lastname: Arcizet