Journal of Radio Electronics. eISSN 1684-1719. 2025. ¹11

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DOI: https://doi.org/10.30898/1684-1719.2025.11.29

 

 

SPINTRONIC THz EMITTERS

BASED ON GRAPHENE AND ANTIFERROMAGNETS

 

A.L. Alferyev 1, A.V. Gorbatova 1, E.A. Bulavintseva 1, A.I. Kartsev 1,

A.A. Klimov 1, A.M. Buryakov 1, N.S. Gusev 2, M.V. Sapozhnikov 1,2

 

1 MIREA-Russian Technological University, 119454, Russia, Moscow, Vernadsky Avenue 78

2 Institute for Physics of Microstructures RAS,

603087, Russia, Nizhny Novgorod region, Kstovsky district, Afonino, Academicheskaya Str. 7

 

The paper was received October 3, 2025.

 

Abstract. We investigate terahertz (THz) emission mechanisms in spintronic emitters – Co (3 nm), graphene (Gr)/Co (3 nm), and Co (3 nm)/FeMn (5 nm) – grown on quartz substrates. Magnetic properties were characterized in the longitudinal magneto-optical Kerr effect (MOKE) geometry, and the emission dynamics by time-domain THz spectroscopy (THz-TDS). In Gr/Co, the graphene interface induces perpendicular magnetic anisotropy; the phase of the THz waveforms is invariant with respect to the pumping side at a fixed field polarity, indicating demagnetization-driven emission. Under back-side pumping the amplitude increases by ≈1.5×, whereas front-side excitation reduces it by about a factor of two, consistent with differences in optical/THz absorption and interference. In Co/FeMn, the antiferromagnetic layer imposes pronounced in-plane uniaxial anisotropy and increases coercivity; a phase inversion upon switching the pumping side indicates a dominant inverse spin Hall effect. No exchange bias is observed at the selected thicknesses and without post-annealing. Additionally, an asymmetry of the THz hysteresis loops in Co/FeMn reveals even-in-magnetization contributions to the emission. These results underscore the central role of interface engineering in Co/AFM and Gr/Co stacks for controlling spin-to-charge conversion and optimizing THz-emitter performance.

Key words: spintronic THz emitter, ultrafast demagnetization, inverse spin Hall effect, graphene, FeMn, perpendicular magnetic anisotropy, MOKE, THz spectroscopy

Financing: The study of the parameters of THz spintronic generators was supported by the Russian Science Foundation (Project No. 24-79-10302). The development and fabrication of spintronic structures using magnetron sputtering was supported by the Ministry of Science and Higher Education of the Russian Federation (Project No. FSFZ-2025-0002). The creation and primary characterization of samples was carried out using equipment from the Center for Collective Use “Physics and Technology of Micro- and Nanostructures” (IPM RAS).

Corresponding author: Alferyev Artem Leonidovich, alferev@mirea.ru

References

1. Heimel G., Brédas J.-L. Reflections on charge transport // Nature Nanotechnology. – 2013. – Vol. 8. – No. 4. – P. 230–231. https://doi.org/10.1038/nnano.2013.42

2. Horiuchi N. On-chip dual-comb source // Nature Photonics. – 2016. – Vol. 10.  – No. 6. – P. 359. https://doi.org/10.1038/nphoton.2016.115

3. Papaioannou E.Th., Beigang R. THz spintronic emitters: a review on achievements and future challenges // Nanophotonics. – 2021. – Vol. 10. – No. 4. – P. 1243–1257. https://doi.org/10.1515/nanoph-2020-0563

4. Khusyainov D., Ovcharenko S., Gaponov M. et al. Polarization control of THz emission using spin-reorientation transition in spintronic heterostructure // Scientific Reports. – 2021. – Vol. 11. – No. 1. – P. 910. https://doi.org/10.1038/s41598-020-80781-5

5. Kampfrath T., Kirilyuk A., Mangin S. et al. Ultrafast and terahertz spintronics: Guest editorial // Applied Physics Letters. – 2023. – Vol. 123. – No. 5. – P. 050001. https://doi.org/10.1063/5.0167151

6. Khusyainov D., Ovcharenko S., Buryakov A. et al. Composite Multiferroic Terahertz Emitter: Polarization Control via an Electric Field // Physical Review Applied. – 2022. – Vol. 17. – No. 4. – P. 044025. https://doi.org/10.1103/PhysRevApplied.17.044025

7. Buryakov A.M., Mishina E.D., Lebedeva E.D. et al. Spin valve as THz emitter providing amplitude modulation // APL Materials. – 2024. – Vol. 12. – No. 10. – P. 101109. https://doi.org/10.1063/5.0221982

8. Bull C., Hewett S.M., Ji R. et al. Spintronic terahertz emitters: Status and prospects from a materials perspective // APL Materials. – 2021. – Vol. 9. – No. 9. – P. 091114. https://doi.org/10.1063/5.0057511

9. Novoselov K.S., Geim A.K., Morozov S.V. et al. Electric Field Effect in Atomically Thin Carbon Films // Science. – 2004. – Vol. 306. – No. 5696. – P. 666–669. https://doi.org/10.1126/science.1102896

10. Alferyev A.L., Kartsev A.I., Shesterikov E.V. et al. Two-dimensional materials for spintronic terahertz emitters // Fine Chemical Technologies. – 2025. – Vol. 13. – No. 4. – P. 47–54. https://doi.org/10.32362/2500-316X-2025-13-4-47-54

11. Eginligil M., Cao B., Wang Z. et al. Dichroic spin–valley photocurrent in monolayer molybdenum disulphide // Nature Communications. – 2015. – Vol. 6. – No. 1. – P. 7636. https://doi.org/10.1038/ncomms8636

12. Mak K.F., He K., Shan J. et al. Control of valley polarization in monolayer MoS2 by optical helicity // Nature Nanotechnology. – 2012. – Vol. 7. – No. 8. – P. 494–498. https://doi.org/10.1038/nnano.2012.96

13. Estevez-Torres A., Rondelez Y. Spatially localized DNA domino // Nature Nanotechnology. – 2017. – Vol. 12. – No. 9. – P. 842–843. https://doi.org/10.1038/nnano.2017.157

14. Panda S.N., Majumder S., Choudhury S. et al. Femtosecond laser-induced spin dynamics in single-layer graphene/CoFeB thin films // Nanoscale. – 2021. – Vol. 13. – No. 32. – P. 13709–13718. https://doi.org/10.1039/d1nr03397b

15. Idzuchi H., Iihama S., Shimura M. et al. Spin injection characteristics of Py/graphene/Pt by gigahertz and terahertz magnetization dynamics driven by femtosecond laser pulse // AIP Advances. – 2021. – Vol. 11. – No. 1. – P. 015014. https://doi.org/10.1063/9.0000114

16. Cheng L., Wang X., Yang W. et al. Far out-of-equilibrium spin populations trigger giant spin injection into atomically thin MoS2 // Nature Physics. – 2019. – Vol. 15. – No. 4. – P. 347–351. https://doi.org/10.1038/s41567-018-0406-3

17. Buryakov A.M., Gorbatova A.V., Avdeev P.Y. et al. Hybrid Co/2D-WSe2-based THz spintronic emitter with tunable polarization // Applied Physics Letters.  – 2025. – Vol. 127. – No. 5. – P. 052402. https://doi.org/10.1063/5.0274793

18. Khusyainov D., Guskov A., Ovcharenko S. et al. Increasing the Efficiency of a Spintronic THz Emitter Based on WSe2/FeCo // Materials. – 2021. – Vol. 14.  – No. 21. – P. 6479. https://doi.org/10.3390/ma14216479

19. Schmidt U., Dieing T., Ibach W. et al. A Confocal Raman-AFM Study of Graphene // Microscopy Today. – 2011. – Vol. 19. – No. 6. – P. 30–33. https://doi.org/10.1017/S1551929511001192

20. Shi Y., Dong X., Chen P. et al. Effective doping of single-layer graphene from underlying SiO2 substrates // Physical Review B. – 2009. – Vol. 79. – No. 11.  – P. 115402. https://doi.org/10.1103/PhysRevB.79.115402

21. Berger A.J., Amamou W., White S.P. et al. Magnetization dynamics of cobalt grown on graphene // Journal of Applied Physics. – 2014. – Vol. 115. – No. 17.  – P. 17C511. https://doi.org/10.1063/1.4864742

22. Yang H., Vu A.D., Hallal A. et al. Anatomy and Giant Enhancement of the Perpendicular Magnetic Anisotropy of Cobalt–Graphene Heterostructures // Nano Letters. – 2016. – Vol. 16. – No. 1. – P. 145–151. https://doi.org/10.1021/acs.nanolett.5b03392

23. Feshchenko A.A., Ezubchenko I.S., Chernov A.I. et al. Effect of thickness and tungsten doping of antiferromagnetic Cr–Mn layers on the microstructure and hysteresis properties of Cr–Mn/FM (FM = Fe, Fe20Ni80, Fe10Co90, Fe60Co20B20) type films // Physics of the Solid State. – 2025. – Vol. 67.  – No. 6. – P. 1101–1111. https://doi.org/10.61011/FTT.2025.06.60962.19HH-25

24. Beaurepaire E., Turner G.M., Harrel S.M. et al. Coherent terahertz emission from ferromagnetic films excited by femtosecond laser pulses // Applied Physics Letters. – 2004. – Vol. 84. – No. 18. – P. 3465–3467. https://doi.org/10.1063/1.1737467

25. Buryakov A.M., Gorbatova A.V., Avdeev P.Yu. et al. Spintronic emitter of terahertz radiation based on two-dimensional semiconductor tungsten diselenide // Technical Physics Letters. – 2022. – Vol. 48. – No. 9. – P. 19–22. https://doi.org/10.21883/PJTF.2022.18.53393.19246

26. Konschuh S., Gmitra M., Fabian J. Tight-binding theory of the spin-orbit coupling in graphene // Physical Review B. – 2010. – Vol. 82. – No. 24. – P. 245412. https://doi.org/10.1103/PhysRevB.82.245412

27. Šipr O., Minár J., Mankovsky S. et al. Influence of composition, many-body effects, spin-orbit coupling, and disorder on magnetism of Co-Pt solid-state systems // Physical Review B. – 2008. – Vol. 78. – No. 14. – P. 144403. https://doi.org/10.1103/PhysRevB.78.144403

28. Tahir M., Sahin H., Meng S. Enhancement of spin current to charge current conversion in Ferromagnet/Graphene interface // arXiv preprint arXiv:2404.16595. – 2024. https://doi.org/10.48550/arXiv.2404.16595

29. Cunha R.O., Garcia-Basabe Y., Larrude D.G. et al. Unraveling the Spin-to-Charge Current Conversion Mechanism and Charge Transfer Dynamics at the Interface of Graphene/WS2 Heterostructures at Room Temperature // ACS Applied Materials & Interfaces. – 2024. – Vol. 16. – No. 36. – P. 48107–48117. https://doi.org/10.1021/acsami.4c08539

30. Abdukayumov K., Mičica M., Ibrahim F. et al. Atomic-Layer Controlled Transition from Inverse Rashba–Edelstein Effect to Inverse Spin Hall Effect in 2D PtSe2 Probed by THz Spintronic Emission // Advanced Materials. – 2024. – Vol. 36. – No. 14. – P. 2304243. https://doi.org/10.1002/adma.202304243

31. Avdeev P.Yu., Gorbatova A.V., Lebedeva E.D. et al. Competing mechanisms of polarization-controlled terahertz emission in Co/Mo spintronic bilayers // Journal of Physics D: Applied Physics. – 2025. – Vol. 58. – No. 38. – P. 385003. https://doi.org/10.1088/1361-6463/ae0345

32. Yao Z., Fu H., Du W. et al. Magnetization-induced optical rectification and inverse spin Hall effect for interfacial terahertz generation in metallic heterostructures // Physical Review B. – 2021. – Vol. 103. – No. 20. – P. L201404. https://doi.org/10.1103/PhysRevB.103.L201404

33. Jiang Y., Li Z., Li Z. et al. Ultrafast light-driven magneto-optical nonlinearity in ferromagnetic heterostructures // Optics Letters. – 2023. – Vol. 48. – No. 8.  – P. 2054–2057. https://doi.org/10.1364/OL.485966

 

For citation:

Alferyev A.L., Gorbatova A.V., Bulavintseva E.A., Kartsev A.I., Klimov A.A., Buryakov A.M., Gusev N.S., Sapozhnikov M.V. Spintronic THz emitters based on graphene and antiferromagnets // Journal of Radio Electronics. – 2025. – ¹. 11. https://doi.org/10.30898/1684-1719.2025.11.29 (In Russian)