title: Actively tunable bistable optical Yagi-Uda nanoantenna.
abstract: We propose and theoretically demonstrate a novel type of optical Yagi-Uda nanoantennas tunable via variation of the free-carrier density of a semiconductor disk placed in a gap of a metallic dipole feeding element. Unlike its narrowband all-metal counterparts, this nanoantenna exhibits a broadband unidirectional emission and demonstrates a bistable response in a preferential direction of the far-field zone, which opens up unique possibilities for ultrafast control of subwavelength light not attainable with dipole or bowtie architectures.
authors.affiliation: Nonlinear Physics Centre and Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200, Australia. mis124@physics.anu.edu.au
authors.forename: Ivan S
authors.initials: IS
authors.lastname: Maksymov
authors.forename: Andrey E
authors.initials: AE
authors.lastname: Miroshnichenko
authors.forename: Yuri S
authors.initials: YS
authors.lastname: Kivshar