title: Nonresonant 104Terahertz Field Enhancement with 5-nm Slits.
abstract: Transmission of Terahertz (THz) electromagnetic wave through a substrate is encumbered because of scattering, multiple reflections, absorption, and Fabry-Perot effects when the wave interacts with the substrate. We present the experimental realization of nonresonant electromagnetic field enhancement by a factor of almost 104in substrate-free 5-nm gold nanoslits. Our nanoslits yielded greater than 90% normalized electric field transmission in the low-frequency THz region; the slit width was 5 nm, and the gap coverage ratio was 10-4of the entire membrane, 0.42 mm2. This large field enhancement was attributed to gap plasmons generated by the THz wave, which squeezes the charge cross-section, thus enabling very highly dense oscillating charges and strong THz field transmission from the nanoslits.
authors.affiliation: Department of Physics and Astronomy and Center for Atom Scale Electromagnetism, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Om Krishna
authors.initials: OK
authors.lastname: Suwal
authors.affiliation: Department of Physics and Astronomy and Center for Atom Scale Electromagnetism, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Jiyeah
authors.initials: J
authors.lastname: Rhie
authors.affiliation: Department of Physics and Astronomy and Center for Atom Scale Electromagnetism, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Nayeon
authors.initials: N
authors.lastname: Kim
authors.affiliation: Department of Physics and Astronomy and Center for Atom Scale Electromagnetism, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Dai-Sik
authors.initials: DS
authors.lastname: Kim