title: Liquid metal-based plasmonics.
abstract: We demonstrate that liquid metals support surface plasmon-polaritons (SPPs) at terahertz (THz) frequencies, and can thus serve as an attractive material system for a wide variety of plasmonic and metamaterial applications. We use eutectic gallium indium (EGaIn) as the liquid metal injected into a polydimethylsiloxane (PDMS) mold fabricated by soft lithography techniques. Using this approach, we observe enhanced THz transmission through a periodic array of subwavelength apertures. Despite of the fact that the DC conductivity of EGaIn is an order of magnitude smaller than many conventional metals, we clearly observe well-defined transmission resonances. This represents a first step in developing reconfigurable and tunable plasmonic devices that build upon well-developed microfluidic capabilities.
authors.affiliation: Department of Physics, University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: Jinqi
authors.initials: J
authors.lastname: Wang
authors.forename: Shuchang
authors.initials: S
authors.lastname: Liu
authors.forename: Z Valy
authors.initials: ZV
authors.lastname: Vardeny
authors.forename: Ajay
authors.initials: A
authors.lastname: Nahata
mesh_terms: D005708:Gallium / Q000737:chemistry*; D007204:Indium / Q000737:chemistry*; D007909:Lenses; D012996:Solutions / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D012996:Solutions; D007204:Indium; D005708:Gallium