title: A universal and ultrasensitive vectorial nanomechanical sensor for imaging 2D force fields.
abstract: The miniaturization of force probes into nanomechanical oscillators enables ultrasensitive investigations of forces on dimensions smaller than their characteristic length scales. It also unravels the vectorial character of the force field and how its topology impacts the measurement. Here we present an ultrasensitive method for imaging two-dimensional vectorial force fields by optomechanically following the bidimensional Brownian motion of a singly clamped nanowire. This approach relies on angular and spectral tomography of its quasi-frequency-degenerated transverse mechanical polarizations: immersing the nanoresonator in a vectorial force field not only shifts its eigenfrequencies but also rotates the orientation of the eigenmodes, as a nanocompass. This universal method is employed to map a tunable electrostatic force field whose spatial gradients can even dominate the intrinsic nanowire properties. Enabling vectorial force field imaging with demonstrated sensitivities of attonewton variations over the nanoprobe Brownian trajectory will have a strong impact on scientific exploration at the nanoscale.
authors.affiliation: University Grenoble Alpes, Institut Néel, F-38000 Grenoble, France.|CNRS, Institut Néel, F-38000 Grenoble, France.
authors.forename: Laure Mercier
authors.initials: LM
authors.lastname: de Lépinay
authors.affiliation: University Grenoble Alpes, Institut Néel, F-38000 Grenoble, France.|CNRS, Institut Néel, F-38000 Grenoble, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Pigeau
authors.affiliation: University Grenoble Alpes, Institut Néel, F-38000 Grenoble, France.|CNRS, Institut Néel, F-38000 Grenoble, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Besga
authors.affiliation: University Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, Villeurbanne F-69622, France.
authors.forename: Pascal
authors.identifier: 0000-0001-5405-9575
authors.initials: P
authors.lastname: Vincent
authors.affiliation: University Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, Villeurbanne F-69622, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Poncharal
authors.affiliation: University Grenoble Alpes, Institut Néel, F-38000 Grenoble, France.|CNRS, Institut Néel, F-38000 Grenoble, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Arcizet