title: Charge Transfer Plasmons: Optical Frequency Conductances and Tunable Infrared Resonances.
abstract: A charge transfer plasmon (CTP) appears when an optical-frequency conductive pathway between two metallic nanoparticles is established, enabling the transfer of charge between nanoparticles when the plasmon is excited. Here we investigate the properties of the CTP in a nanowire-bridged dimer geometry. Varying the junction geometry controls its conductance, which modifies the resonance energies and scattering intensities of the CTP while also altering the other plasmon modes of the nanostructure. Reducing the junction conductance shifts this resonance to substantially lower energies in the near- and mid-infrared regions of the spectrum. The CTP offers both a high-information probe of optical frequency conductances in nanoscale junctions and a new, unique approach to controllably engineering tunable plasmon modes at infrared wavelengths.
authors.affiliation: †Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, and ∥Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Wen
authors.affiliation: †Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, and ∥Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: †Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, and ∥Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States.
authors.forename: Samuel
authors.initials: S
authors.lastname: Gottheim
authors.affiliation: †Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, and ∥Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States.
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: King
authors.affiliation: †Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, and ∥Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: †Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, and ∥Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Nordlander
authors.affiliation: †Department of Chemistry, ‡Department of Physics and Astronomy, §Department of Electrical and Computer Engineering, and ∥Laboratory for Nanophotonics, Rice University, Houston, Texas 77005, United States.
authors.forename: Naomi J
authors.initials: NJ
authors.lastname: Halas
keywords: IR plasmon; charge transfer plasmon; electric current; electron beam lithography; optical antenna; single-particle dark-field spectroscopy