title: Magnetic-field enhancement in gold nanosandwiches.
abstract: Using dispersive finite-difference time-domain (D-FDTD) simulations, we show that a pair of gold nanodisks stacked in a 'sandwich'-like (end-fire) configuration produces a large enhancement of the magnetic field when irradiated with a plane optical wave, if the distance between the nanodisks is optically small. The effect, which can be rationalized in terms of a magnetic dipole resonance, is due the excitation of a hybridized asymmetric plasmon mode, in which the induced electrical dipoles in the two disks oscillate out-of-phase. The strong magnetic response, together with the simple morphology, suggests that Au nanosandwiches are suitable elementary building blocks for optical metamaterials that exhibit negative refraction.
authors.forename: T
authors.initials: T
authors.lastname: Pakizeh
authors.forename: M S
authors.initials: MS
authors.lastname: Abrishamian
authors.forename: N
authors.initials: N
authors.lastname: Granpayeh
authors.forename: A
authors.initials: A
authors.lastname: Dmitriev
authors.forename: M
authors.initials: M
authors.lastname: Käll