Novel layout of a bi-metallic nanoring for magnetic field pulse generation from light

Abstract

Recently Tsiatmas et al proposed using a nanoring made of two different metallic sectors to generate a magnetic pulse from a laser pulse [1]. Non-uniform heating of the ring creates very large temperature gradients, which drive thermoelectric currents, and this creates a localized magnetic field. However, heat from the laser pulse may result in the melting of the nanoring. We propose a symmetric structure made of four metallic sectors, which results in a higher magnetic field generation together with a lower lattice temperature. We also show that the magnetic field depends strongly on the size of the metallic sectors and interpret the results with the help of the electromotive forces, the overall ring resistance, and Biot-Savart law.

Magneto-optical response in bimetallic metamaterials

“…We expect bimetallic metamaterials to find applications in refractive index and magnetic field sensing, as well as in compact active components for integrated nanophotonic circuits. In addition, this design has been shown to support transient thermoelectric currents that give rise to magnetic pulses [18,19].…”

“…Moreover, changing the wavelength or polarization of the incident light allows one to shift the area of light confinement along the resonator and thus control the MO response. Finally, our approach is based on continuous metallic nanostructures and enables not only to realize complex resonators with prescribed MO and plasmonic response but also to exploit other types of physical response involving thermal and electric effects [18,19].…”

Plasmonic absorption properties of bimetallic metamaterials

“…Our results offer an effective way to control field enhancement and consequently dissipation losses at particular areas of the 6 ring resonators, which can be used in applications where site-specific heating is essential. Finally, bimetallic hybrids exhibit a variety of interesting properties like differential thermal expansion or the ability to generate thermoelectric currents, that can be used, for example, in the generation of THz magnetic pulses [8,9].…”

“…On the other hand, there are applications which require strong optical absorption and maximizing the dissipation losses is actually desirable [1]. A few examples include the use of plasmonic metamaterials in order to enhance photoemission [2][3][4], form water vapour [5], generate electricity [6,7] and thermoelectrically driven magnetic pulses [8,9]. In principle, the increased absorption cross-section that nanostructures offer [10] is an effective mechanism to transfer energy from light to matter.…”

Ultraintense Femtosecond Magnetic Nanoprobes Induced by Azimuthally Polarized Laser Beams

“…However, such interactions require the use of intense magnetic fields. Although in the last years Tesla-scale magnetic fields have been reported at the nanosecond and picosecond time scales, through laser–plasma interaction, or benefiting from transient thermoelectric currents in metals, , to the best of our knowledge, there is no evidence of the generation of such intense, isolated, magnetic fields in the fs time scale.…”