title: Active terahertz nanoantennas based on VO2 phase transition.
abstract: Unusual performances of metamaterials such as negative index of refraction, memory effect, and cloaking originate from the resonance features of the metallic composite atom(1-6). Indeed, control of metamaterial properties by changing dielectric environments of thin films below the metallic resonators has been demonstrated(7-11). However, the dynamic control ranges are still limited to less than a factor of 10,(7-11) with the applicable bandwidth defined by the sharp resonance features. Here, we present ultra-broad-band metamaterial thin film with colossal dynamic control range, fulfilling present day research demands. Hybridized with thin VO(2) (vanadium dioxide) (12-18) films, nanoresonator supercell arrays designed for one decade of spectral width in terahertz frequency region show an unprecedented extinction ratio of over 10000 when the underlying thin film experiences a phase transition. Our nanoresonator approach realizes the full potential of the thin film technology for long wavelength applications.
authors.affiliation: Center for Subwavelength Optics and Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
authors.forename: Minah
authors.initials: M
authors.lastname: Seo
authors.forename: Jisoo
authors.initials: J
authors.lastname: Kyoung
authors.forename: Hyeongryeol
authors.initials: H
authors.lastname: Park
authors.forename: Sukmo
authors.initials: S
authors.lastname: Koo
authors.forename: Hyun-sun
authors.initials: HS
authors.lastname: Kim
authors.forename: Hannes
authors.initials: H
authors.lastname: Bernien
authors.forename: Bong Jun
authors.initials: BJ
authors.lastname: Kim
authors.forename: Jong Ho
authors.initials: JH
authors.lastname: Choe
authors.forename: Yeong Hwan
authors.initials: YH
authors.lastname: Ahn
authors.forename: Hyun-Tak
authors.initials: HT
authors.lastname: Kim
authors.forename: Namkyoo
authors.initials: N
authors.lastname: Park
authors.forename: Q-Han
authors.initials: QH
authors.lastname: Park
authors.forename: Kwangjun
authors.initials: K
authors.lastname: Ahn
authors.forename: Dai-sik
authors.initials: DS
authors.lastname: Kim