title: Spontaneous symmetry breaking in two coupled nanomechanical electron shuttles.
abstract: We present spontaneous symmetry breaking in a nanoscale version of a setup prolific in classical mechanics: two coupled nanomechanical pendula. The two pendula are electron shuttles fabricated as nanopillars [D. V. Scheible and R. H. Blick, Appl. Phys. Lett. 84, 4632 (2004).10.1063/1.1759371] and placed between two capacitor plates in a homogeneous electric field. Instead of being mechanically coupled through a spring they exchange electrons, i.e., they shuttle electrons from the source to the drain "capacitor plate." The nonzero dc current through this system by external ac excitation is caused via dynamical symmetry breaking. This symmetry-broken current appears at sub- and superharmonics of the fundamental mode of the coupled system.
authors.affiliation: University of Wisconsin-Madison, Electrical & Computer Engineering, 1415 Engineering Drive, Madison, Wisconsin 53706, USA.
authors.forename: Chulki
authors.initials: C
authors.lastname: Kim
authors.forename: Jonghoo
authors.initials: J
authors.lastname: Park
authors.forename: Robert H
authors.initials: RH
authors.lastname: Blick