title: Nonconservative dynamics of optically trapped high-aspect-ratio nanowires.
abstract: We investigate the dynamics of high-aspect-ratio nanowires trapped axially in a single gradient force optical tweezers. A power spectrum analysis of the dynamics reveals a broad spectral resonance of the order of kHz with peak properties that are strongly dependent on the input trapping power. A dynamical model incorporating linear restoring optical forces, a nonconservative asymmetric coupling between translational and rotational degrees of freedom, viscous drag, and white noise provides an excellent fit to experimental observations. A persistent low-frequency cyclical motion around the equilibrium trapping position, with a frequency distinct from the spectral resonance, is observed from the time series data.
authors.affiliation: School of Physics, The University of New South Wales, Sydney NSW 2052, Australia.
authors.forename: Wen Jun
authors.initials: WJ
authors.lastname: Toe
authors.affiliation: School of Mathematics and Statistics, The University of New South Wales, Sydney NSW 2052, Australia.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Ortega-Piwonka
authors.affiliation: School of Mathematics and Statistics, The University of New South Wales, Sydney NSW 2052, Australia.
authors.forename: Christopher N
authors.initials: CN
authors.lastname: Angstmann
authors.affiliation: Research School of Physics and Engineering, The Australian National University, Canberra ACT 2601, Australia.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Gao
authors.affiliation: Research School of Physics and Engineering, The Australian National University, Canberra ACT 2601, Australia.
authors.forename: Hark Hoe
authors.initials: HH
authors.lastname: Tan
authors.affiliation: Research School of Physics and Engineering, The Australian National University, Canberra ACT 2601, Australia.
authors.forename: Chennupati
authors.initials: C
authors.lastname: Jagadish
authors.affiliation: School of Mathematics and Statistics, The University of New South Wales, Sydney NSW 2052, Australia.
authors.forename: Bruce I
authors.initials: BI
authors.lastname: Henry
authors.affiliation: School of Physics, The University of New South Wales, Sydney NSW 2052, Australia.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Reece