title: Sharp Toroidal Resonances in Planar Terahertz Metasurfaces.
abstract: A toroidal dipole in metasurfaces provides an alternate approach for the excitation of high-Q resonances. In contrast to conventional multipoles, the toroidal dipole interaction strength depends on the time derivative of the surrounding electric field. A characteristic feature of toroidal dipoles is tightly confined loops of oscillating magnetic field that curl around the fictitious arrow of the toroidal dipole vector.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.|Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, Singapore, 639798, Singapore.
authors.forename: Manoj
authors.initials: M
authors.lastname: Gupta
authors.affiliation: Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, United Kingdom.
authors.forename: Vassili
authors.initials: V
authors.lastname: Savinov
authors.affiliation: School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: Ningning
authors.initials: N
authors.lastname: Xu
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.|Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, Singapore, 639798, Singapore.
authors.forename: Longqing
authors.initials: L
authors.lastname: Cong
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.|Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, Singapore, 639798, Singapore.
authors.forename: Govind
authors.initials: G
authors.lastname: Dayal
authors.affiliation: Department of Electronic Engineering, Tianjin University of Technology and Education, Tianjin, 300222, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Wang
authors.affiliation: School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: Weili
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.|Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, Singapore, 639798, Singapore.|Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, United Kingdom.
authors.forename: Nikolay I
authors.initials: NI
authors.lastname: Zheludev
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore. ranjans@ntu.edu.sg.|Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, Singapore, 639798, Singapore. ranjans@ntu.edu.sg.
authors.forename: Ranjan
authors.initials: R
authors.lastname: Singh
keywords: high-Q resonances; magnetic coupling; metasurfaces; terahertz; toroidal dipoles