title: Magnetic modulation of surface plasmon modes in magnetoplasmonic metal-insulator-metal cavities.
abstract: The magnetic modulation of the surface plasmon-polariton (SPP) wavevector is experimentally and theoretically studied for the plasmonic modes excited in metal-insulator-metal (MIM) magnetoplasmonic cavities. For this purpose, Ag/SiO₂/Ag multilayers with different SiO₂ layer thickness in which a thin Co layer is positioned near the top Ag/SiO₂ interface, near the bottom SiO₂/Ag one, or near both of them, are studied. The magnetoplasmonic MIM cavities present symmetric (SM) and antisymmetric (AM) plasmonic modes, of different wavevector and electromagnetic field profiles inside the MIM cavity. We show that the magnetic SPP wavevector modulation strongly depends on which mode is considered, the cavity thickness, and the number and specific location of Co layers within the structure. With only one ferromagnetic layer, a net modulation is obtained, of higher magnitude as we reduce the SiO₂ layer thickness. The introduction of a second Co layer in the structure reduces the modulation due to the non-reciprocal character of SPP modes under an applied magnetic field. Moreover, we demonstrate that the non-reciprocal nature of the SPP modulation can be experimentally visualized in the magnetic hysteresis loops under plasmon excitation conditions by using two Co layers with different magnetization switching fields.
authors.affiliation: IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, E-28760 Tres Cantos, Madrid, Spain. elias@imm.cnm.csic.es
authors.forename: E
authors.initials: E
authors.lastname: Ferreiro-Vila
authors.forename: J M
authors.initials: JM
authors.lastname: García-Martín
authors.forename: A
authors.initials: A
authors.lastname: Cebollada
authors.forename: G
authors.initials: G
authors.lastname: Armelles
authors.forename: M U
authors.initials: MU
authors.lastname: González
mesh_terms: D004553:Electric Conductivity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D060526:Magnetic Fields; D059346:Magnets; D012822:Silicon Dioxide / Q000737:chemistry* / Q000528:radiation effects; D012834:Silver / Q000737:chemistry* / Q000528:radiation effects; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D012834:Silver; D012822:Silicon Dioxide