title: Nonradiating anapole modes in dielectric nanoparticles.
abstract: Nonradiating current configurations attract attention of physicists for many years as possible models of stable atoms. One intriguing example of such a nonradiating source is known as 'anapole'. An anapole mode can be viewed as a composition of electric and toroidal dipole moments, resulting in destructive interference of the radiation fields due to similarity of their far-field scattering patterns. Here we demonstrate experimentally that dielectric nanoparticles can exhibit a radiationless anapole mode in visible. We achieve the spectral overlap of the toroidal and electric dipole modes through a geometry tuning, and observe a highly pronounced dip in the far-field scattering accompanied by the specific near-field distribution associated with the anapole mode. The anapole physics provides a unique playground for the study of electromagnetic properties of nontrivial excitations of complex fields, reciprocity violation and Aharonov-Bohm like phenomena at optical frequencies.
authors: Nonlinear Physics Centre, The Australian National University, Acton, Australian Capital Territory 2601, Australia.
authors: Andrey E
authors: AE
authors: Miroshnichenko
authors: Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hannover, Germany.|Institute of Laser and Information Technologies RAS, 142190 Moscow, Troitsk, Russia.
authors: Andrey B
authors: AB
authors: Evlyukhin
authors: Data Storage Institute, A*STAR, 5 Engineering Drive 1, 117608, Singapore.
authors: Ye Feng
authors: YF
authors: Yu
authors: Data Storage Institute, A*STAR, 5 Engineering Drive 1, 117608, Singapore.
authors: Reuben M
authors: RM
authors: Bakker
authors: Technische Universität Darmstadt, Institut für Mikrowellentechnik und Photonik, Merckstraße 25, 64283 Darmstadt.
authors: Arkadi
authors: A
authors: Chipouline
authors: Data Storage Institute, A*STAR, 5 Engineering Drive 1, 117608, Singapore.
authors: Arseniy I
authors: AI
authors: Kuznetsov
authors: Data Storage Institute, A*STAR, 5 Engineering Drive 1, 117608, Singapore.
authors: Boris
authors: B
authors: Luk'yanchuk
authors: Laser Zentrum Hannover e.V., Hollerithallee 8, D-30419 Hannover, Germany.|Institute of Laser and Information Technologies RAS, 142190 Moscow, Troitsk, Russia.|Saint-Petersburg Polytechnic University, Polytechnicheskaya 29, 195251 St Petersburg, Russia.
authors: Boris N
authors: BN
authors: Chichkov
authors: Nonlinear Physics Centre, The Australian National University, Acton, Australian Capital Territory 2601, Australia.
authors: Yuri S
authors: YS
authors: Kivshar