title: Scattering efficiency and near field enhancement of active semiconductor plasmonic antennas at terahertz frequencies.
abstract: Terahertz plasmonic resonances in semiconductor (indium antimonide, InSb) dimer antennas are investigated theoretically. The antennas are formed by two rods separated by a small gap. We demonstrate that, with an appropriate choice of the shape and dimension of the semiconductor antennas, it is possible to obtain large electromagnetic field enhancement inside the gap. Unlike metallic antennas, the enhancement around the semiconductor plasmonics antenna can be easily adjusted by varying the concentration of free carriers, which can be achieved by optical or thermal excitation of carriers or electrical carrier injection. Such active plasmonic antennas are interesting structures for THz applications such as modulators and sensors.
authors.affiliation: FOM Institute for Atomic and Molecular Physics AMOLF, Philips Research Laboratories, High Tech Campus 4, 5656 AE, Eindhoven, The Netherlands. giannini@amolf.nl
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Giannini
authors.forename: Audrey
authors.initials: A
authors.lastname: Berrier
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Maier
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Sánchez-Gil
authors.forename: Jaime Gómez
authors.initials: JG
authors.lastname: Rivas