Ultrafast spin-transfer torque driven by femtosecond pulsed-laser excitation

Schellekens, A. J.; Kuiper, K. C.; Wit, R.R.J.C. de; Koopmans, B.

doi:10.1038/ncomms5333

Cited by 180 publications

(170 citation statements)

References 42 publications

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“…These effects offer to exploit non-local magnetization dynamics. Already now femtosecond (fs) laser-excited spin currents in layer stacks were reported to induce spin transfer torque [13]. Furthermore, laser-induced spin currents in a magnetic tunnel junction were controlled by a bias voltage [14].…”

Section: Introductionmentioning

confidence: 99%

Separation of ultrafast spin currents and spin-flip scattering in Co/Cu(001) driven by femtosecond laser excitation employing the complex magneto-optical Kerr effect

et al. 2015

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Ultrafast magnetization dynamics in metallic heterostructures consists of a combination of local demagnetization in the ferromagnetic constituent and spin-dependent transport contributions within and in between the constituents. Separation of these local and non-local contributions is essential to obtain microscopic understanding and for potential applications of the underlying microscopic processes. By comparing the ultrafast changes of the polarization rotation and ellipticity in the magneto-optical Kerr effect (MOKE) we observe a time-dependent magnetization profile M (z, t) in Co/Cu(001) films by exploiting the effective depth sensitivity of the method. By analyzing the spatio-temporal correlation of these profiles we find that on time scales before hot electron thermalization (< 100 fs) the transient magnetization of Co films is governed by spin-dependent transport effects, while after hot electron thermalization (> 200 fs) local spin-flip processes dominate.

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Section: Introductionmentioning

confidence: 99%

Separation of ultrafast spin currents and spin-flip scattering in Co/Cu(001) driven by femtosecond laser excitation employing the complex magneto-optical Kerr effect

et al. 2015

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“…Also, the spin-transfer torque effect is operative on THz frequencies. 54 Magnetic RAMs currently are operated by magnetic tunnel junction based bits. It is essential to manipulate magnetization in such bits in a controlled way by the application of a spin torque.…”

Section: Novel Applications In the Thz Range A Thz Spintronicsmentioning

confidence: 99%

Perspective: Ultrafast magnetism and THz spintronics

Walowski

Münzenberg

2016

Journal of Applied Physics

325

205

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This year the discovery of femtosecond demagnetization by laser pulses is 20 years old. For the first time, this milestone work by Bigot and coworkers gave insight directly into the time scales of microscopic interactions that connect the spin and electron system. While intense discussions in the field were fueled by the complexity of the processes in the past, it now became evident that it is a puzzle of many different parts. Rather than providing an overview that has been presented in previous reviews on ultrafast processes in ferromagnets, this perspective will show that with our current depth of knowledge the first applications are developed: THz spintronics and all-optical spin manipulation are becoming more and more feasible. The aim of this perspective is to point out where we can connect the different puzzle pieces of understanding gathered over 20 years to develop novel applications. Based on many observations in a large number of experiments. Differences in the theoretical models arise from the localized and delocalized nature of ferromagnetism. Transport effects are intrinsically non-local in spintronic devices and at interfaces. We review the need for multiscale modeling to address the processes starting from electronic excitation of the spin system on the picometer length scale and sub-femtosecond time scale, to spin wave generation, and towards the modeling of ultrafast phase transitions that altogether determine the response time of the ferromagnetic system. Today, our current understanding gives rise to the first usage of ultrafast spin physics for ultrafast magnetism control: THz spintronic devices. This makes the field of ultrafast spin-dynamics an emerging topic open for many researchers right now. Published by AIP Publishing. [http://dx

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“…While spin currents have been proven to be relevant on femtosecond time scales [11,15,16], only few details are known about the amount of optically induced spin currents or spin injection efficiency across various interfaces.…”

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confidence: 99%