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Optical determination of the Néel vector in a CuMnAs thin-film antiferromagnet

Abstract

Recent breakthroughs in the electrical detection and manipulation of antiferromagnets have opened a new avenue in the research of non-volatile spintronic devices1,2,3,4,5,6,7,8,9,10. Antiparallel spin sublattices in antiferromagnets, producing zero dipolar fields, lead to insensitivity to magnetic field perturbations, multi-level stability, ultrafast spin dynamics and other favourable characteristics, and may find utility in fields ranging from magnetic memories to optical signal processing. However, the absence of a net magnetic moment and ultrashort magnetization dynamics timescales make antiferromagnets notoriously difficult to study using common magnetometers or magnetic resonance techniques. Here, we demonstrate the experimental determination of the Néel vector in a thin film of antiferromagnetic CuMnAs (refs 9,10), a prominent material used in the first realization of antiferromagnetic memory chips10. We use a table-top femtosecond pump–probe magneto-optical experiment that is considerably more accessible than the traditionally employed large-scale-facility techniques such as neutron diffraction11 and X-ray magnetic dichroism measurements12,13,14,15,16.

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Figure 1: Experimental observation of uniaxial magnetic anisotropy in a 10 nm film of CuMnAs.
Figure 2: Determination of spin axis direction by the MO experiment.
Figure 3: Verification of spin axis direction by XMLD.
Figure 4: Determination of Néel temperature.

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References

  1. Shick, A. B., Khmelevskyi, S., Mryasov, O. N., Wunderlich, J. & Jungwirth, T. Spin–orbit coupling induced anisotropy effects in bimetallic antiferromagnets: a route towards antiferromagnetic spintronics. Phys. Rev. B 81, 212409 (2010).

    Article  ADS  Google Scholar 

  2. MacDonald, A. H. & Tsoi, M. Antiferromagnetic metal spintronics. Phil. Trans. R. Soc. A 369, 3098–3114 (2011).

    Article  ADS  Google Scholar 

  3. Park, B. G. et al. A spin-valve-like magnetoresistance of an antiferromagnet-based tunnel junction. Nat. Mater. 10, 347–351 (2011).

    Article  ADS  Google Scholar 

  4. Barthem, V. M. T. S., Colin, C. V., Mayaffre, H., Julien, M. H. & Givord, D. Revealing the properties of Mn2Au for antiferromagnetic spintronics. Nat. Commun. 4, 2892 (2013).

    Article  ADS  Google Scholar 

  5. Marti, X. et al. Room-temperature antiferromagnetic memory resistor. Nat. Mater. 13, 367–374 (2014).

    Article  ADS  Google Scholar 

  6. Kriegner, D. et al. Multiple-stable anisotropic magnetoresistance memory in antiferromagnetic MnTe. Nat. Commun. 7, 11623 (2016).

    Article  ADS  Google Scholar 

  7. Gomonay, E. V. & Loktev, V. M. Spintronics of antiferromagnetic systems. Low Temp. Phys. 40, 17–35 (2014).

    Article  ADS  Google Scholar 

  8. Jungwirth, T., Marti, X., Wadley, P. & Wunderlich, J. Antiferromagnetic spintronics. Nat. Nanotech. 11, 231–241 (2016).

    Article  ADS  Google Scholar 

  9. Wadley, P. et al. Tetragonal phase of epitaxial room-temperature antiferromagnet CuMnAs. Nat. Commun. 4, 2322 (2013).

    Article  ADS  Google Scholar 

  10. Wadley, P . et al. Electrical switching of an antiferromagnet. Science 351, 587–590 (2016).

    Article  ADS  Google Scholar 

  11. Schreyer, A. et al. Neutron scattering on magnetic thin films: pushing the limits. J. Appl. Phys. 87, 5443–5448 (2000).

    Article  ADS  Google Scholar 

  12. Alders, D. et al. Temperature and thickness dependence of magnetic moments in NiO epitaxial films. Phys. Rev. B 57, 11623 (1998).

    Article  ADS  Google Scholar 

  13. Kuiper, P., Searle, B. G., Rudolf, P., Tjeng, L. H. & Chen, C. T. X-ray magnetic dichroism of antiferromagnet Fe2O3: the orientation of magnetic moments observed by Fe 2p X-ray absorption spectroscopy. Phys. Rev. Lett. 70, 1549–1552 (1993).

    Article  ADS  Google Scholar 

  14. Mertins, H.-C. H. et al. Observation of the X-ray magneto-optical Voigt effect. Phys. Rev. Lett. 87, 047401 (2001).

    Article  ADS  Google Scholar 

  15. Mertins, H.-C. et al. Magneto-optical polarization spectroscopy with soft X-rays. Appl. Phys. A 80, 1011–1020 (2005).

    Article  ADS  Google Scholar 

  16. Valencia, S. et al. Quadratic X-ray magneto-optical effect upon reflection in a near-normal-incidence configuration at the M edges of 3d-transition metals. Phys. Rev. Lett. 104, 187401 (2010).

    Article  ADS  Google Scholar 

  17. Zvezdin, A. K. & Kotov, V. A. Modern Magnetooptics and Magnetooptical Materials (Institute of Physics, 1997).

    Book  Google Scholar 

  18. McCord, J. Progress in magnetic domain observation by advanced magneto-optical microscopy. J. Phys. D 48, 333001 (2015).

    Article  Google Scholar 

  19. Kirilyuk, A., Kimel, A. V. & Rasing, T. Ultrafast optical manipulation of magnetic order. Rev. Mod. Phys. 82, 2731–2784 (2010).

    Article  ADS  Google Scholar 

  20. Kimel, A. V., Kirilyuk, A., Tsvetkov, A., Pisarev, R. V. & Rasing, T. Laser-induced ultrafast spin reorientation in the antiferromagnet TmFeO3 . Nature 429, 850–853 (2004).

    Article  ADS  Google Scholar 

  21. Kimel, A. V. et al. Ultrafast non-thermal control of magnetization by instantaneous photomagnetic pulses. Nature 435, 655–657 (2005).

    Article  ADS  Google Scholar 

  22. Kimel, A. V. et al. Inertia-driven spin switching in antiferromagnets. Nat. Phys. 5, 727–731 (2009).

    Article  Google Scholar 

  23. Kampfrath, T. et al. Coherent terahertz control of antiferromagnetic spin waves. Nat. Photon. 5, 31–34 (2011).

    Article  ADS  Google Scholar 

  24. Ferre, J. & Gehring, G. A. Linear optical birefringence of magnetic crystals. Rep. Prog. Phys. 47, 513–611 (1984).

    Article  ADS  Google Scholar 

  25. Tesarova, N. et al. Systematic study of magnetic linear dichroism and birefringence in (Ga,Mn)As. Phys. Rev. B 89, 085203 (2014).

    Article  ADS  Google Scholar 

  26. Bossini, D. et al. Macrospin dynamics in antiferromagnets triggered by sub-20 femtosecond injection of nanomagnons. Nat. Commun. 7, 10645 (2016).

    Article  ADS  Google Scholar 

  27. Tesarova, N. et al. Direct measurement of the three-dimensional magnetization vector trajectory in GaMnAs by a magneto-optical pump-and-probe method. Appl. Phys. Lett. 100, 102403 (2012).

    Article  ADS  Google Scholar 

  28. Tesarova, N. et al. Experimental observation of the optical spin–orbit torque. Nat. Photon. 7, 492–498 (2013).

    Article  ADS  Google Scholar 

  29. Tesarova, N. et al. High precision magnetic linear dichroism measurements in (Ga,Mn)As. Rev. Sci. Instrum. 83, 123108 (2012).

    Article  ADS  Google Scholar 

  30. Wadley, P. et al. Antiferromagnetic structure in tetragonal CuMnAs thin films. Sci. Rep. 5, 17079 (2015).

    Article  ADS  Google Scholar 

  31. Beaurepaire, E., Merle, J.-C., Daunois, A. & Bigot, J.-Y. Ultrafast spin dynamics in ferromagnetic nickel. Phys. Rev. Lett. 76, 4250–4253 (1996).

    Article  ADS  Google Scholar 

  32. Bigot, J.-Y., Vomir, M. & Beaurepaire, E. Coherent ultrafast magnetism induced by femtosecond laser pulses. Nat. Phys. 5, 515–520 (2009).

    Article  Google Scholar 

  33. Kunes, J. & Oppeneer, P. M. Anisotropic X-ray magnetic linear dichroism at the L2,3 edges of cubic Fe, Co, and Ni: ab initio calculations and model theory. Phys. Rev. B 67, 024431 (2003).

    Article  ADS  Google Scholar 

  34. Kneedler, E. M. et al. Influence of substrate surface reconstruction on the growth and magnetic properties of Fe on GaAs(001). Phys. Rev. B 56, 8163–8168 (1997).

    Article  ADS  Google Scholar 

  35. Moosbühler, R., Bensch, F., Dumm, M. & Bayreuther, G. Epitaxial Fe films on GaAs(001): does the substrate surface reconstruction affect the uniaxial magnetic anisotropy? J. Appl. Phys. 91, 8757–8759 (2002).

    Article  ADS  Google Scholar 

  36. Hills, V. et al. Paramagnetic to antiferromagnetic transition in epitaxial tetragonal CuMnAs. J. Appl. Phys. 117, 172608 (2015).

    Article  ADS  Google Scholar 

  37. Rozkotova, E. et al. Coherent control of magnetization precession in ferromagnetic semiconductor (Ga,Mn)As. Appl. Phys. Lett. 93, 232505 (2008).

    Article  ADS  Google Scholar 

  38. Koopmans, B., Kampen, M., Kohlhepp, J. T. & Jonge, W. J. M Ultrafast magneto-optics in nickel: magnetism or optics? Phys. Rev. Lett. 85, 844–847 (2000).

    Article  ADS  Google Scholar 

  39. Horodyska, P. et al. Exciton spin dynamics in spherical CdS quantum dots. Phys. Rev. B 81, 045301 (2010).

    Article  ADS  Google Scholar 

  40. Carpene, E. et al. Dynamics of electron–magnon interaction and ultrafast demagnetization in thin iron films. Phys. Rev. B 78, 174422 (2008).

    Article  ADS  Google Scholar 

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Acknowledgements

This work was supported by the Grant Agency of the Czech Republic (grant no. 14-37427G), by the EU ERC (advanced grant no. 268066), by the Ministry of Education of the Czech Republic (grant no. LM2015087), by the University of Nottingham EPSRC Impact Acceleration Account and by the Grant Agency of Charles University in Prague (grants nos. 1910214 and SVV–2015–260216). The authors acknowledge the Diamond Light Source for the provision of beamtime (proposal no. SI-9993).

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Contributions

R.P.C., V.H. and V.N. prepared the samples. P.N., P.W., B.L.G., P.M. and T.J. planned the experiments. V.S. and F.T. performed the MO experiments. V.H. performed the electrical measurements. P.W., K.W.E., F.M. and S.S.D. performed the XMLD experiment. J.K. and J.Z. performed the XMLD calculations. P.N., V.S. and T.J. wrote the manuscript with contributions from all authors.

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Correspondence to P. Němec.

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The authors declare no competing financial interests.

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Saidl, V., Němec, P., Wadley, P. et al. Optical determination of the Néel vector in a CuMnAs thin-film antiferromagnet. Nature Photon 11, 91–96 (2017). https://doi.org/10.1038/nphoton.2016.255

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