title: Cooling of nanomechanical resonators by thermally activated single-electron transport.
abstract: We show that the vibrations of a nanomechanical resonator can be cooled to near its quantum ground state by tunneling injection of electrons from a scanning tunneling microscope tip. The interplay between two mechanisms for coupling the electronic and mechanical degrees of freedom results in a bias-voltage-dependent difference between the probability amplitudes for vibron emission and absorption during tunneling. For a bias voltage just below the Coulomb blockade threshold, we find that absorption dominates, which leads to cooling corresponding to an average vibron population of the fundamental bending mode of 0.2.
authors.affiliation: Department of Physics, University of Gothenburg, Göteborg, Sweden.
authors.forename: F
authors.initials: F
authors.lastname: Santandrea
authors.forename: L Y
authors.initials: LY
authors.lastname: Gorelik
authors.forename: R I
authors.initials: RI
authors.lastname: Shekhter
authors.forename: M
authors.initials: M
authors.lastname: Jonson