Terahertz emission from magnetic thin film and patterned heterostructures

Sergi Lendinez*, Yi Li, Weipeng Wu, Mojtaba Taghipour Kaffash, Qi Zhang, Wei Zhang, John E. Pearson, Ralu Divan, Richard D. Schaller, Axel Hoffmann, Haidan Wen, Matthias Benjamin Jungfleisch

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

In recent years terahertz (THz) technology has been an emerging research field with a broad range of applications. THz radiation falls between the infrared and microwave radiation in the electromagnetic spectrum. Most THz sources to date are not related to the spin degree of freedom; however, recent research efforts in spintronics and ferromagnetism demonstrated that the electron spin offers completely new opportunities for the generation of ultrafast photocurrents. For instance, magnetic heterostructures are very easy to pattern and potentially allow to tailor THz emission characteristics by design. Here, we demonstrate that an ultrafast spin-current pulse driven by a femtosecond laser pulse can create THz transients in microstructured magnetic heterostructures due to the inverse spin Hall effect. We compare the THz electric field and the THz spectrum of a control CoFeBPt film with microstructured CoFeBPt wires as well as microstructured CoFeBMgO wires patterned on an extended Pt film. We find that the THz electric field amplitude is proportional to the coverage of the CoFeBPt heterostructure on top of the MgO substrate. Furthermore, we analyze the magnetization direction dependence of the THz transients with respect to the easy axis of the ferromagnetic wire. The presented results are the first steps towards shaping and controlling the THz properties by microstructuring of spintronics-based THz emitters.

Original languageEnglish (US)
Title of host publicationSpintronics XII
EditorsHenri-Jean M. Drouhin, Jean-Eric Wegrowe, Manijeh Razeghi, Henri Jaffres
PublisherSPIE
ISBN (Electronic)9781510628731
DOIs
StatePublished - Jan 1 2019
EventSpintronics XII 2019 - San Diego, United States
Duration: Aug 11 2019Aug 15 2019

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume11090
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Conference

ConferenceSpintronics XII 2019
CountryUnited States
CitySan Diego
Period8/11/198/15/19

Keywords

  • Magnetic microstructure
  • Spin Hall effect
  • Spintronics
  • Terahertz spintronics

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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  • Cite this

    Lendinez, S., Li, Y., Wu, W., Taghipour Kaffash, M., Zhang, Q., Zhang, W., Pearson, J. E., Divan, R., Schaller, R. D., Hoffmann, A., Wen, H., & Jungfleisch, M. B. (2019). Terahertz emission from magnetic thin film and patterned heterostructures. In H-J. M. Drouhin, J-E. Wegrowe, M. Razeghi, & H. Jaffres (Eds.), Spintronics XII [1109013] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 11090). SPIE. https://doi.org/10.1117/12.2526194