title: Ubiquitous mechanisms of energy dissipation in noncontact atomic force microscopy.
abstract: Atomistic simulations considering larger tip structures than hitherto assumed reveal novel dissipation mechanisms in noncontact atomic force microscopy. The potential energy surfaces of realistic silicon tips exhibit many energetically close local minima that correspond to different structures. Most of them easily deform, thus causing dissipation arising from hysteresis in force versus distance characteristics. Furthermore, saddle points which connect local minima can suddenly switch to connect different minima. Configurations driven into metastability by the tip motion can thus suddenly access lower energy structures when thermal activation becomes allowed within the time required to detect the resulting average dissipation.
authors.affiliation: Department of Physics and National Center for Research in Nanoscale Science, University of Basel, Basel, Switzerland.
authors.forename: S Alireza
authors.initials: SA
authors.lastname: Ghasemi
authors.forename: Stefan
authors.initials: S
authors.lastname: Goedecker
authors.forename: Alexis
authors.initials: A
authors.lastname: Baratoff
authors.forename: Thomas
authors.initials: T
authors.lastname: Lenosky
authors.forename: Ernst
authors.initials: E
authors.lastname: Meyer
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Hug