Abstract
The idea to use not only the charge but also the spin of electrons in the operation of electronic devices has led to the development of spintronics, causing a revolution in how information is stored and processed. A novel advancement would be to develop ultrafast spintronics using femtosecond laser pulses. Employing terahertz (1012 Hz) emission spectroscopy and exploiting the spin–orbit interaction, we demonstrate the optical generation of electric photocurrents in metallic ferromagnetic heterostructures at the femtosecond timescale. The direction of the photocurrent is controlled by the helicity of the circularly polarized light. These results open up new opportunities for realizing spintronics in the unprecedented terahertz regime and provide new insights in all-optical control of magnetism.
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Acknowledgements
The authors thank T. Toonen, A. van Etteger and S. Semin for technical support and A. Brataas, A. Kirilyuk, A.K. Zvezdin and V.V. Bel'kov for discussions. This work was supported by the Foundation for Fundamental Research on Matter (FOM), the European Union's Seventh Framework Programme (FP7/2007-2013) grants no. 280555 (Go-Fast) and no. 281043 (FemtoSpin), projects no. Norte-070124-FEDER-000070 and no. FEDER-POCTI/0155, European Research Council grants no. 257280 (Femtomagnetism) and no. 339813 (Exchange), and the ‘Leading Scientist’ programme of the Russian Ministry of Education and Science (14.Z50.31.0034). J.D.C. acknowledges FCT grant no. SFRH/BD/7939/2011.
Author information
Affiliations
Radboud University, Institute for Molecules and Materials, 6525 AJ Nijmegen, The Netherlands
- T. J. Huisman
- , R. V. Mikhaylovskiy
- , Th. Rasing
- & A. V. Kimel
INL - International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga s/n, 4715-330 Braga, Portugal
- J. D. Costa
- , E. Paz
- & P. P. Freitas
IN-IFIMUP, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal
- J. D. Costa
- & J. Ventura
Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany
- F. Freimuth
- , S. Blügel
- & Y. Mokrousov
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Contributions
T.J.H., R.V.M., J.D.C. and A.V.K. conceived the experiments. T.J.H. and R.V.M. designed and built the experimental set-up. T.J.H. performed the measurements and analysed the data with help from R.V.M. and A.V.K. J.D.C. fabricated and characterized the samples with help from E.P., J.V. and P.P.F. The theoretical formalisms were derived by T.J.H., R.V.M. and F.F., with contributions from Y.M., S.B. and A.V.K. T.J.H., R.V.M., F.F. and A.V.K. co-wrote the paper. All authors discussed the results and commented on the manuscript. The project was coordinated by A.V.K.
Competing interests
The authors declare no competing financial interests.
Corresponding author
Correspondence to T. J. Huisman.
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