Thermomagnetic control of spintronic THz emission enabled by ferrimagnets

Fix, Mario; Schneider, Robert; Bensmann, Jannis; Vasconcellos, Steffen Michaelis de; Bratschitsch, Rudolf; Albrecht, Manfred

doi:10.1063/1.5132624

Cited by 29 publications

(10 citation statements)

References 34 publications

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“…Among the many different types of terahertz (THz) emitters using various physical effects, spintronic ones demonstrate many noticeable advantages, primarily ultra-broad bandwidth but also a high efficiency and ease of control of radiation parameters: polarization [1][2][3][4], amplitude [5,6], phase [7]. Benefits such as an ease of integration and low cost allow spintronic emitters to be integrated into a variety of end-user devices for spectroscopy, medicine and safety.…”

Section: Introductionmentioning

confidence: 99%

Increasing the Efficiency of a Spintronic THz Emitter Based on WSe2/FeCo

et al. 2021

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We report an increase in terahertz (THz) radiation efficiency due to FeCo/WSe2 structures in the reflection geometry. This can be attributed to an absorption increase in the alloy FeCo layer at the input FeCo/WSe2 interface due to constructive interference, as well as to the backward transport of hot carriers from FeCo to WSe2. In contrast to the transmission geometry, the THz generation efficiency in the reflection is much less dependent on the magnetic layer thickness. Our results suggest a cheap and efficient way to improve the characteristics of THz spintronic emitters with the conservation of a full set of their important properties.

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Section: Introductionmentioning

confidence: 99%

Increasing the Efficiency of a Spintronic THz Emitter Based on WSe2/FeCo

et al. 2021

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“…Previous studies report that the amplitude and timescale of demagnetization may depend on temperature when the ferromagnet is in proximity to a magnetic phase transition. [11][12][13][14][15] In this work, we use cobalt as a spin source because of its large Curie temperature (T C = 1388 K in bulk 16 ), meaning that below room temperature the system is far from any magnetic transition. We show that the thermal variation in this case is not set by the spin source (Co), which exhibits temperature independent magnetization and demagnetization dynamics, but instead by the spin Hall resistivity of our chosen transduction layer (Pt).…”

mentioning

confidence: 99%

Temperature dependent inverse spin Hall effect in Co/Pt spintronic emitters

Matthiesen

Afanasiev

Hortensius

et al. 2020

Applied Physics Letters

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In bilayers of ferromagnets and heavy metals, which form the so-called spintronic emitters, the phenomena of ultrafast demagnetization and the inverse spin Hall effect (ISHE) conspire to yield remarkably efficient emission of electric pulses in the THz band. Light-induced demagnetization of the ferromagnet launches a pulse of spin current into the heavy metal, wherein it bifurcates into a radiative charge transient due to the ISHE. The influence of temperature on this combined effect should depend on both the magnetic phase diagram and the microscopic origin of spin Hall conductivity, but its exact dependence remains to be clarified. Here, we experimentally study the temperature dependence of an archetypal spintronic emitter, the Co/Pt bilayer, using electro-optic sampling of the emitted THz pulses in the time domain. The emission amplitude is attenuated with decreasing temperature, consistent with an inverse spin Hall effect in platinum of predominantly intrinsic origin.

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“…In particular, it should also be applicable to metallic antiferromagnets such as CuMnAs and Mn 2 Au that have recently moved into the focus of spintronics research 11,38 . In this way, THz AMR complements other recently developed ultrafast spintronic techniques such as THz anomalous Hall effect 39,40 and magnetization-dependent THz emission 41,42,43 that have provided new insights into the dynamics of spin transport and spin-to-chargecurrent conversion.…”

Section: Discussionmentioning

confidence: 87%

Broadband Terahertz Probes of Anisotropic Magnetoresistance Disentangle Extrinsic and Intrinsic Contributions

et al. 2021

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Anisotropic magnetoresistance (AMR) is a ubiquitous and versatile probe of ferro-, ferri-and antiferromagnetic order in contemporary spintronics research. Its origins are usually ascribed to spin-dependent electron scattering, whereas scattering-independent (intrinsic) contributions are neglected. Here, we measure AMR of the standard ferromagnets Co, Ni, Ni 81 Fe 19 and Ni 50 Fe 50 over the very wide frequency range from DC to 28 THz, which covers the regimes of both diffusive and ballistic transport. Analysis of the broadband response based on Boltzmann-Drude theory reveals that the AMR not only has the familiar scattering-dependent contribution, but also contains a sizeable scattering-independent component. In polycrystalline Co, this component is frequency-independent up to 28 THz and amounts to more than 2/3 of the AMR contrast of 1%, thereby making it interesting for applications in terahertz spintronics and terahertz photonics. Our results show that broadband terahertz electromagnetic pulses provide new insights into magneto-transport phenomena of magnetic materials on ultrafast time scales.

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Thermomagnetic control of spintronic THz emission enabled by ferrimagnets

Cited by 29 publications

References 34 publications

Increasing the Efficiency of a Spintronic THz Emitter Based on WSe2/FeCo

Increasing the Efficiency of a Spintronic THz Emitter Based on WSe2/FeCo

Temperature dependent inverse spin Hall effect in Co/Pt spintronic emitters

Broadband Terahertz Probes of Anisotropic Magnetoresistance Disentangle Extrinsic and Intrinsic Contributions

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