Exploring the Fundamental Spatial Limits of Magnetic All-Optical Switching.
Felix SteinbachUnai AtxitiaKelvin YaoMartin BorchertDieter W EngelFilippo BencivengaLaura FogliaRiccardo MincigrucciEmanuele PedersoliDario De AngelisMatteo PancaldiDanny FainozziJacopo Stefano Pelli CresiEttore PaltaninFlavio CapotondiClaudio MasciovecchioStefan EisebittClemens von Korff SchmisingPublished in: Nano letters (2024)
All-optical switching (AOS) results in ultrafast and deterministic magnetization reversal upon single laser pulse excitation, potentially supporting faster and more energy-efficient data storage. To explore the fundamental limits of achievable bit densities in AOS, we have used soft X-ray transient grating spectroscopy to study the ultrafast magnetic response of a GdFe alloy after a spatially structured excitation with a periodicity of 17 nm. The ultrafast spatial evolution of the magnetization in combination with atomistic spin dynamics and microscopic temperature model calculations allows us to derive a detailed phase diagram of AOS as a function of both the absorbed energy density and the nanoscale excitation period. Our results suggest that the minimum size for AOS in GdFe alloys, induced by a nanoscale periodic excitation, is around 25 nm and that this limit is governed by ultrafast lateral electron diffusion and by the threshold for optical damage.
Keyphrases
- energy transfer
- high resolution
- high speed
- atomic force microscopy
- quantum dots
- molecular dynamics simulations
- density functional theory
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- molecularly imprinted
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- electron transfer
- oxidative stress
- molecular dynamics
- electronic health record
- mass spectrometry
- minimally invasive
- magnetic resonance imaging
- blood brain barrier
- electron microscopy
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