@article{14b59aea95814ce78830b7dc07df14df,
title = "Optical Anapole Metamaterial",
abstract = "The toroidal dipole is a localized electromagnetic excitation independent from the familiar magnetic and electric dipoles. It corresponds to currents flowing along minor loops of a torus. Interference of radiating induced toroidal and electric dipoles leads to anapole, a nonradiating charge-current configuration. Interactions of induced toroidal dipoles with electromagnetic waves have recently been observed in artificial media at microwave, terahertz, and optical frequencies. Here, we demonstrate a quasi-planar plasmonic metamaterial, a combination of dumbbell aperture and vertical split-ring resonator, that exhibits transverse toroidal moment and resonant anapole behavior in the optical part of the spectrum upon excitation with a normally incident electromagnetic wave. Our results prove experimentally that toroidal modes and anapole modes can provide distinct and physically significant contributions to the absorption and dispersion of slabs of matter in the optical part of the spectrum in conventional transmission and reflection experiments.",
author = "Wu, {Pin Chieh} and Liao, {Chun Yen} and Vassili Savinov and Chung, {Tsung Lin} and Chen, {Wei Ting} and Huang, {Yao Wei} and Wu, {Pei Ru} and Chen, {Yi Hao} and Liu, {Ai Qun} and Zheludev, {Nikolay I.} and Tsai, {Din Ping}",
note = "Funding Information: The authors acknowledge financial support from the Ministry of Science and Technology, Taiwan (Grant No.: MOST-106-2745-M-002-003-ASP) and Academia Sinica (Grant No.: AS-103-TP-A06), the UK Engineering and Physical Sciences Research Council (Grant: EP/M009122/1), and the Singapore Ministry of Education (Grant: MOE2011-T3-1-005). They are also grateful to the National Center for Theoretical Sciences, NEMS Research Center of National Taiwan University, National Center for High-Performance Computing, Taiwan, and Research Center for Applied Sciences, Academia Sinica, Taiwan, for their supports. Following a period of embargo, the data from this article can be obtained from the University of Southampton research repository https://doi.org/10.5258/SOTON/D0136. Funding Information: The authors acknowledge financial support from the Ministry of Science and Technology, Taiwan (Grant No.: MOST-106-2745-M-002-003-ASP) and Academia Sinica (Grant No.: AS-103-TP-A06), the UK Engineering and Physical Sciences Research Council (Grant: EP/M009122/1), and the Singapore Ministry of Education (Grant: MOE2011-T3-1-005). They are also grateful to the National Center for Theoretical Sciences NEMS Research Center of National Taiwan University, National Center for High-Performance Computing, Taiwan, and Research Center for Applied Sciences, Academia Sinica, Taiwan, for their supports. Publisher Copyright: {\textcopyright} 2018 American Chemical Society.",
year = "2018",
month = feb,
day = "27",
doi = "10.1021/acsnano.7b08828",
language = "English",
volume = "12",
pages = "1920--1927",
journal = "ACS Nano",
issn = "1936-0851",
publisher = "American Chemical Society",
number = "2",
}