May 15 – 20, 2022
Hotel Hermitage, La Biodola Bay, Elba Island, Italy
Europe/Rome timezone

Ferromagnetic Resonance in a Nickel thin film driven by optically-excited Surface Acoustic Waves (SAWs) in a Transient Grating (TG) setup

May 16, 2022, 5:40 PM
20m
Hotel Hermitage, La Biodola Bay, Elba Island, Italy

Hotel Hermitage, La Biodola Bay, Elba Island, Italy

Biodola Bay 57037 Portoferraio (LI) Isola d’Elba - Italy
Oral

Speaker

Pietro Carrara (Università degli Studi di Milano)

Description

Moore-ruled down-scaling of magnetic bits in new-generation memories hampers deterministic switching and calls for new techniques for magnetization manipulation. Acoustic control of magnetism is an appealing route for low-energy-consumption operation, e.g. exploiting magneto-elastic coupling (MEC) in a thin-film planar heterostructure, where SAWs at micron-size wavelength drive magnetization precession by inverse magnetostriction [1].
We studied MEC in Nickel films (8-40 nm) deposited on amorphous and crystalline substrates. We employed a four-wave-mixing approach [2] in a UHV-ready TG-spectroscopy setup, with a 300 fs, high frequency laser (NFFA-SPRINT*). Two pump pulses thermally excite SAWs, which couple to magnetostatic waves. A third time-delayed pulse acts either as acoustic (TG diffraction), or as magnetic probe (Faraday rotation). Tuning an external magnetic field, the condition of SAW-driven ferromagnetic resonance (FMR) is reached: the time-dependent magneto-elastic field balances the Gilbert damping, allowing spin precession to last long after its natural damping. The range of wavevectors studied (few inverse microns) allows a comparison with results from standard FMR in terms of Kittel curve and extrinsic contribution to the magnetic damping.

*https://www.trieste.nffa.eu/techniques/spectroscopy/tg-sprint/

[1] W.Yang and H.Schmidt, Appl.Phys.Rev. 8, 021304 (2021)
[2] J.Janušonis et al. Sci.Rep. 6.1, 1-10 (2016)

Primary authors

Deepak Dagur (Università degli Studi di Trieste) Emanuele Longo (CNR IMM) Giancarlo Panaccione (CNR IOM) Giorgio Rossi (Università degli Studi di Milano) Giovanni Vinai (CNR IOM) Marco Fanciulli (Università degli Studi di Milano Bicocca) Marta Brioschi (Università degli Studi di Milano) Pietro Carrara (Università degli Studi di Milano) Riccardo Cucini (CNR IOM) Roberto Mantovan (CNR IMM) Vincent Polewczyk (CNR IOM)

Presentation materials