Efficient spin excitation via ultrafast damping-like torques in antiferromagnets

1. Gomonay, O., Baltz, V., Brataas, A. & Tserkovnyak, Y. Antiferromagnetic spin textures and dynamics. Nat. Phys. 14, 213–216 (2018).

2. Baltz, V. et al. Antiferromagnetic spintronics. Rev. Mod. Phys. 90, 015005 (2018).

3. Wienholdt, S., Hinzke, D. & Nowak, U. THz switching of antiferromagnets and ferrimagnets. Phys. Rev. Lett. 108, 247207 (2012).

4. Němec, P., Fiebig, M., Kampfrath, T. & Kimel, A. V. Antiferromagnetic opto- spintronics. Nat. Phys. 14, 229–241 (2018).

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

6. Yang, S.-H., Ryu, K.-S. & Parkin, S. Domain-wall velocities of up to 750 m s−1 driven by exchange-coupling torque in synthetic antiferromagnets. Nat. Nanotechnol. 10, 221–226 (2015).

7. Hellman, F. et al. Interface-induced phenomena in magnetism. Rev. Mod. Phys. 89, 025006 (2017).

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

9. Kalashnikova, A. M. et al. Impulsive generation of coherent magnons by linearly polarized light in the easy-plane antiferromagnet FeBO3. Phys. Rev. Lett. 99, 167205 (2007).

10. Satoh, T. et al. Spin oscillations in antiferromagnetic NiO triggered by circularly polarized light. Phys. Rev. Lett. 105, 077402 (2010).

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

12. Kalashnikova, A. M., Kimel, A. V. & Pisarev, R. V. Ultrafast opto-magnetism. Phys. Usp. 58, 969–980 (2015).

13. Bossini, D. & Rasing, T. Femtosecond optomagnetism in dielectric antiferromagnets. Phys. Scr. 92, 024002 (2017).

14. Tzschaschel, C. et al. Ultrafast optical excitation of coherent magnons in antiferromagnetic NiO. Phys. Rev. B 95, 174407 (2017).

15. Tzschaschel, C., Satoh, T. & Fiebig, M. Tracking the ultrafast motion of an antiferromagnetic order parameter. Nat. Commun. 10, 3995 (2019).

16. Kittel, C. Introduction to Solid State Physics 8th edn. (Wiley, New York, 2004).

17. Kalashnikova, A. M. et al. Impulsive excitation of coherent magnons and phonons by subpicosecond laser pulses in the weak ferromagnet FeBO3. Phys. Rev. B 78, 104301 (2008).

18. Satoh, T., Iida, R., Higuchi, T., Fiebig, M. & Shimura, T. Writing and reading of an arbitrary optical polarization state in an antiferromagnet. Nat. Photon. 9, 25–29 (2015).

19. Landau, L. D., Pitaevskii, L. P. & Lifshitz, E. M. Electrodynamics of Continuous Media 2nd edn, Vol. 8 (Course of Theoretical Physics) (Butterworth- Heinemann, London, 1984).

20. Devolder, T., Hayakawa, J., Ito, K., Takahashi, H. & Ikeda, S. et al. Single-shot time-resolved measurements of nanosecond-scale spin-transfer induced switching: stochastic versus deterministic aspects. Phys. Rev. Lett. 100, 057206 (2008).

21. Fiebig, M., Pavlov, V. V. & Pisarev, R. V. Second-harmonic generation as a tool for studying electronic and magnetic structures of crystals: review. J. Opt. Soc. Am. B 22, 96–118 (2005).

22. Fiebig, M., Lottermoser, T. & Pisarev, R. V. Spin-rotation phenomena and magnetic phase diagrams of hexagonal RMnO3. J. Appl. Phys. 93, 8194–8196 (2003).

23. Lottermoser, T. & Fiebig, M. Magnetoelectric behavior of domain walls in multiferroic HoMnO3. Phys. Rev. B 70, 220407 (2004).

24. Fabrèges, X. et al. Interplay between spin dynamics and crystal field in multiferroic compound HoMnO3. Phys. Rev. B 100, 094437 (2019).

25. Toulouse, C. et al. Lattice and spin excitations in multiferroic h-YMnO3. Phys. Rev. B 89, 094415 (2014).

26. Hansteen, F., Kimel, A., Kirilyuk, A. & Rasing, T. Femtosecond photomagnetic switching of spins in ferrimagnetic garnet films. Phys. Rev. Lett. 95, 047402 (2005).

27. Hansteen, F., Kimel, A., Kirilyuk, A. & Rasing, T. Nonthermal ultrafast optical control of the magnetization in garnet films. Phys. Rev. B 73, 014421 (2006).

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

29. Ivanov, B. A. Spin dynamics of antiferromagnets under action of femtosecond laser pulses (review article). Low Temp. Phys. 40, 91–105 (2014).

30. Khan, P., Kanamaru, M., Matsumoto, K., Ito, T. & Satoh, T. Ultrafast light- driven simultaneous excitation of coherent terahertz magnons and phonons in multiferroic BiFeO3. Phys. Rev. B. 101, 134413 (2020).

31. Talbayev, D. et al. Magnetic exchange interaction between rare-earth and mn ions in multiferroic hexagonal manganites. Phys. Rev. Lett. 101, 247601 (2008).

32. Laurita, N. J. et al. Asymmetric splitting of an antiferromagnetic resonance via quartic exchange interactions in multiferroic hexagonal HoMnO3. Phys. Rev. Lett. 119, 227601 (2017).

33. Krivoruchko, V. N. Spin waves damping in nanometre-scale magnetic materials (review article). Low Temp. Phys. 41, 670–681 (2015).

34. Pailhès, S. et al. Hybrid Goldstone modes in multiferroic YMnO3 studied by polarized inelastic neutron scattering. Phys. Rev. B 79, 134409 (2009).

35. Němec, P. et al. Experimental observation of the optical spin transfer torque. Nat. Phys. 8, 411–415 (2012).

36. Choi, G.-M., Schreife, André & Cahill, D. G. Optical-helicity-driven magnetization dynamics in metallic ferromagnets. Nat. Commun. 8, 15085 (2017).

37. Pavlov, V. V. et al. Magnetic-field-induced crossover from the inverse Faraday effect to the optical orientation in EuTe. J. Appl. Phys. 123, 193102 (2018).

38. Baierl, S. et al. Terahertz-driven nonlinear spin response of antiferromagnetic nickel oxide. Phys. Rev. Lett. 117, 197201 (2016).

39. Malinowski, G. et al. Control of speed and efficiency of ultrafast demagnetization by direct transfer of spin angular momentum. Nat. Phys. 4, 855–858 (2008).

40. Schellekens, A. J., Kuiper, K. C., de Wit, R. & Koopmans, B. Ultrafast spin- transfer torque driven by femtosecond pulsed-laser excitation. Nat. Commun. 5, 4333 (2014).

41. Manchon, A. et al. Current-induced spin-orbit torques in ferromagnetic and antiferromagnetic systems. Rev. Mod. Phys. 91, 035004 (2019).

42. Kalashnikova, A. M. & Pisarev, R. V. Electronic structure of hexagonal rare- earth manganites RMnO3. JETP Lett. 78, 143 (2003).

43. Bossini, D., Kalashnikova, A. M., Pisarev, R. V., Rasing, T. & Kimel, A. V. Controlling coherent and incoherent spin dynamics by steering the photoinduced energy flow. Phys. Rev. B 89, 060405 (2014).

44. Standard, E. C., Stanislavchuk, T., Sirenko, A. A., Lee, N. & Cheong, S.-W. Magnons and crystal-field transitions in hexagonal RMnO3 (R = Er, Tm, Yb, Lu) single crystals. Phys. Rev. B 85, 144422 (2012).

45. Moriyama, T. et al. Intrinsic and extrinsic antiferromagnetic damping in NiO. Phys. Rev. Mater. 3, 051402 (2019).

46. Ratcliff, W., Lynn, J. W., Kiryukhin, V., Jain, P. & Fitzsimmons, M. R. Magnetic structures and dynamics of multiferroic systems obtained with neutron scattering. npj Quant. Mater. 1, 16003 (2016).