Frequency-independent terahertz anomalous Hall effect in DyCo${}_5$, Co${}_{32}$Fe${}_{68}$ and Gd${}_{27}$Fe${}_{73}$ thin films from DC to 40 THz

Abstract

The anomalous Hall effect (AHE) is a fundamental spintronic charge-to-charge-current conversion phenomenon and closely related to spin-to-charge-current conversion by the spin Hall effect. Future high-speed spintronic devices will crucially rely on such conversion effects at terahertz (THz) frequencies. Here, we reveal that the AHE remains operative from DC up to 40 THz with a flat frequency response in thin films of three technologically relevant magnetic materials: DyCo${}_5$, Co${}_{32}$Fe${}_{68}$ and Gd${}_{27}$Fe${}_{73}$. We measure the frequency-dependent conductivity-tensor elements ${\sigma }_{xx}$ and ${\sigma }_{yx}$ and find good agreement with DC measurements. Our experimental findings are fully consistent with ab-initio calculations of ${\sigma }_{yx}$ for CoFe and highlight the role of the large Drude scattering rate (~100 THz) of metal thin films, which smears out any sharp spectral features of the THz AHE. Finally, we find that the intrinsic contribution to the THz AHE dominates over the extrinsic mechanisms for the Co${}_{32}$Fe${}_{68}$ sample. The results imply that the AHE and related effects such as the spin Hall effect are highly promising ingredients of future THz spintronic devices reliably operating from DC to 40 THz and beyond.

References in corpus (10)

• Perspective: Ultrafast magnetism and THz spintronics
• Semiclassical theories of the anomalous Hall effect
• Powerful and Tunable THz Emitters Based on the Fe/Pt Magnetic Heterostructure
• Intrinsic spin currents in ferromagnets
• Infrared dielectric properties of low-stress silicon nitride
• Observation of intrinsic inverse spin Hall effect
• Terahertz conductivity of the magnetic Weyl semimetal Mn${}_3$Sn films
• Determination of the infrared complex magneto-conductivity tensor in itinerant ferromagnets from Faraday and Kerr measurements
• Sub 100-ps dynamics of the anomalous Hall effect at THz frequencies
• Thickness-dependent electron momentum relaxation times in iron films

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• Ultrafast Dynamics of Intrinsic Anomalous Hall Effect in the Topological Antiferromagnet Mn3Sn
• Direct evidence of terahertz emission arising from anomalous Hall effect
• Impact of gigahertz and terahertz transport regimes on spin propagation and conversion in the antiferromagnet IrMn
• Accessing ultrafast spin-transport dynamics in copper using broadband terahertz spectroscopy
• Observation of Terahertz Spin Hall Conductivity Spectrum in GaAs with Optical Spin Injection
• Transient grating spectroscopy on a DyCo${}_5$ thin film with femtosecond extreme ultraviolet pulses
• Terahertz time-domain signatures of the inverse Edelstein effect in topological-insulator|ferromagnet heterostructures
• Terahertz magneto-optical response in ferromagnetic Fe-Co-Al alloys
• Berry Curvature Dipole-Induced Chiral Terahertz Gain and Lasing Threshold in Bulk Tellurium
• Sensor free, self regulating thermal switching via anomalous Ettingshausen effect and spin reorientation in DyCo5