Search

Your search keyword '"Carfagno, H."' showing total 4 results
Start Over Author "Carfagno, H."
4 results on '"Carfagno, H."'

1. A Brillouin light scattering study of the spin-wave magnetic field dependence in a magnetic hybrid system made of an artificial spin-ice structure and a film underlayer

Author

Montoncello, F., Kaffash, M. T., Carfagno, H., Doty, M. F., Gubbiotti, G., and Jungfleisch, M. B.

Subjects
Condensed Matter - Materials Science, Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Applied Physics
Abstract

We present a combined Brillouin light scattering and micromagnetic simulation investigation of the magnetic-field dependent spin-wave spectra in a hybrid structure made of permalloy (NiFe) artificial spin-ice (ASI) systems, composed of stadium-shaped nanoislands, deposited on the top of an unpatterned permalloy film with a nonmagnetic spacer layer. The thermal spin-wave spectra were recorded by Brillouin light scattering (BLS) as a function of the magnetic field applied along the symmetry direction of the ASI sample. Magneto-optic Kerr effect magnetometry was used to measure the hysteresis loops in the same orientation as the BLS measurements. The frequency and intensity of several spin-wave modes detected by BLS were measured as a function of the applied magnetic field. Micromagnetic simulations enabled us to identify the modes in terms of their frequency and spatial symmetry and to extract information about the existence and strength of the dynamic coupling, relevant only to a few modes of a given hybrid system. Using this approach, we suggest a way to understand if dynamic coupling between ASI and film modes is present or not, with interesting implications for the development of future three-dimensional magnonic applications and devices.

Published
2023
Full Text
View/download PDF

4. A sleeve and bulk method for fabrication of photonic structures with features on multiple length scales.

Author

Carfagno, H S, McCabe, L N, Zide, J M O, and Doty, M F

Subjects
*PHOTONIC crystals, *LEAD, *ORDER picking systems, *NANOFABRICATION, *NUCLEAR track detectors
Abstract

Traditional photonic structures such as photonic crystals utilize (a) large arrays of small features with the same size and pitch and (b) a small number of larger features such as diffraction outcouplers. In conventional nanofabrication, separate lithography and etch steps are used for small and large features in order to employ process parameters that lead to optimal pattern transfer and side-wall profiles for each feature-size category, thereby overcoming challenges associated with reactive ion etching lag. This approach cannot be scaled to more complex photonic structures such as those emerging from inverse design protocols. Those structures include features with a large range of sizes such that no distinction between small and large can be made. We develop a sleeve and bulk etch protocol that can be employed to simultaneously pattern features over a wide range of sizes while preserving the desired pattern transfer fidelity and sidewall profiles. This approach reduces the time required to develop a robust process flow, simplifies the fabrication of devices with wider ranges of feature sizes, and enables the fabrication of devices with increasingly complex structure. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results