title: Dynamical backaction cooling with free electrons.
abstract: The ability to cool single ions, atomic ensembles, and more recently macroscopic degrees of freedom down to the quantum ground state has generated considerable progress and perspectives in fundamental and technological science. These major advances have been essentially obtained by coupling mechanical motion to a resonant electromagnetic degree of freedom in what is generally known as laser cooling. Here, we experimentally demonstrate the first self-induced coherent cooling mechanism that is not mediated by an electromagnetic resonance. Using a focused electron beam, we report a 50-fold reduction of the motional temperature of a nanowire. Our result primarily relies on the sub-nanometre confinement of the electron beam and generalizes to any delayed and spatially confined interaction, with important consequences for near-field microscopy and fundamental nanoscale dissipation mechanisms.
authors.affiliation: Laboratoire de Physique Statistique de l'Ecole Normale Supérieure, UMR8550, ENS, 24, rue Lhomond, 75005 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Niguès
authors.affiliation: Laboratoire de Physique Statistique de l'Ecole Normale Supérieure, UMR8550, ENS, 24, rue Lhomond, 75005 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Siria
authors.affiliation: Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne Cedex, France.
authors.forename: P
authors.identifier: http://orcid.org/0000-0002-5105-3319
authors.initials: P
authors.lastname: Verlot