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Antiferromagnetic coulpling in spintronics

Antiferromagnetic coulpling in spintronics. Tom as Jungwirth. Institute of Physics ASCR & Charles Univ. , Czech Rep. Univ. of Nottingham, UK. Hitachi and Univ. Cambridge , UK & Japan. Politecnico di Milano, Italy. Univ. of California, Berkeley.

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Antiferromagnetic coulpling in spintronics

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  1. Antiferromagnetic coulpling in spintronics Tomas Jungwirth Institute of Physics ASCR & Charles Univ., Czech Rep. Univ. of Nottingham, UK Hitachi and Univ. Cambridge, UK & Japan Politecnico di Milano, Italy Univ. of California, Berkeley Institut de Ciencia deMaterials de Barcelona, Spain

  2. Giant magnetoresistance (GMR) multilayers: the dawn of spintronics Fert, Grünberg, et al. 1988 Nobel Prize 2007 Antiferromagnetic arrangement of a ferromagnetic multilayer at B=0

  3. Writing information in spin-valve: towards spintronic memory (MRAM) 1. AFM coupling between FMs at B=0 FM FM FM FM FM FM 2. One FM flips harder than the other FM Soft FM Soft FM 3. One FM pinned by AFM material Soft FM Soft FM Hard FM Hard FM Fixed FM Fixed FM AFM AFM

  4. Towards reliable switching of a particular MRAM bit Soft FM NM Fixed FM AFM

  5. Toggle switching  first commercial MRAMs FM “Synthetic AFM“ FM Fixed FM AFM

  6. Read-out: Giant magnetoresistance (GMR) Ie Ie Fert, Grünberg, et al. 1988 Nobel Prize 2007

  7. Read-out: Anisotropic magnetoresistance (AMR) Spintronic effect 150 years ahead of time M Ie Kelvin, 1857

  8. Read-out: Anisotropic magnetoresistance (AMR) Spintronic effect 150 years ahead of time M Ie Kelvin, 1857

  9. Ohmic AMR Kelvin, 1857 Magnetization-orientation-dependent scattering Relativistic spin-orbit coupling

  10. Ohmic GMR Fert, Grünberg, 1988 Spin-channel-dependent scattering Non-relativistic

  11. Tunneling magnetoresistance (TMR) Julliere 1975, Moodera et al., Miyazaki& Tezuka1995 MRAM Spin-channel-dependent tunneling DOS Non-relativistic

  12. Tunneling anisotopic magnetoresistance (TAMR) Gould, TJ et al. PRL ‘04 Magnetization-orientation-dependent tunneling DOS Relativistic spin-orbit coupling

  13. Two paradigms for spintronics “Mott“ two-spin-channel model of ferromagnets I I Mott, 1936 “Dirac“ relativistic spin-orbit coupling I I Dirac, 1928

  14. Mott with ferromagnets Mott with antiferromagnets Antiferromagnetic MATERIALS playing ACTIVE role in spintronics FM FM Fixed FM AFM Dirac with ferromagnets Dirac with antiferromagnets I I I I I I AFM I I

  15. Spin-valve with AFM electrode Park, Marti, Wunderlich,TJ et al. Nature Mat. ’11, PRL ’12 Pt NiFe MgO NiFe MnIr Ta/Ru/Ta

  16. Spin-valve with AFM electrode Park, Marti, Wunderlich,TJ et al. Nature Mat. ’11, PRL ’12 NiFe Pt MgO NiFe MnIr Ta/Ru/Ta

  17. Spin-valve with AFM electrode Park, Marti, Wunderlich,TJ et al. Nature Mat. ’11, PRL ’12 Pt MgO NiFe Ta/Ru/Ta MnIr

  18. Spin-valve with AFM electrode Park, Marti, Wunderlich,TJ et al. Nature Mat. ’11, PRL ’12 100 1.5 & 3nm IrMn R [k] Pt MgO MnIr 50 4K -1 0 1 B [ T ] >100% spin-valve-like signal at ~50 mT NiFe Ta/Ru/Ta

  19. Spin-valve with AFM electrode Park, Marti, Wunderlich,TJ et al. Nature Mat. ’11, PRL ’12 Pt MgO MnIr Electrically measurable memory effect in AFM NiFe Ta/Ru/Ta

  20. Spin-valve with AFM electrode Park, Marti, Wunderlich,TJ et al. Nature Mat. ’11, PRL ’12 Pt MgO MnIr Small signal in control sample without IrMn NiFe Ta/Ru/Ta

  21. Spin-valve with AFM electrode Writing by exchange-spring rotation of AFM by FM Scholl et al. PRL ‘04 B [ o ] 100 R [k] 50 See also Wang et al. PRL ’12: room-T AFM TAMR in CoPt/IrMn/AlOx/Pt -1 0 1 B [ T ]

  22. Spin-valve with AFM electrode Shick, TJ et al. PRB ’10 see also Zemen, TJ et al. arXiv:1301.5369 50 AFM  DOS/DOS 0 100 spin-orbit coupling R [k] 50 -1 0 1 -50 B [ T ] -0.2 0 0.2 Energy (eV)

  23. Spin-valve with AFM electrode Relativistic ab initio density-of-states anisotropy Antiferromagnets Ferromagnets IrMn, AuMn,... 50 (DOS001 – DOS110)/DOS 0 Shick, Wunderlich, TJ et al. PRB ‘10 Park, Wunderlich, Joo, Jung, Shin, TJ et al. PRL’08 -50 -0.2 0 0.2 Energy (eV)

  24. AFM tunnel junction written by field-cool without FM Petti, Marti, Bertacco, TJ et al., submitted to APL ‘13 Pt MgO MnIr NiFe Ta/Ru/Ta

  25. AFM tunnel junction written by field-cool without FM Petti, Marti, Bertacco, TJ et al., submitted to APL ‘13 Pt MgO MnIr NiFe Ta/Ru/Ta

  26. AFM tunnel junction written by field-cool without FM Petti, Marti, Bertacco, TJ et al., submitted to APL ‘13 Pt MgO MnIr Field thermal-assisted MRAM Ta/Ru/Ta

  27. AFM tunnel junction written by field-cool without FM Petti, Marti, Bertacco, TJ et al., submitted to APL ‘13 z B Pt x MgO y MnIr (RH-RL)/RL (%) Magnetic memory insensitive to magnetic fields& producing no stray fields Ta/Ru/Ta

  28. Writing by current: non-relativistic spin-transfer torque Spins injected from external polarizer in a non-uniform magnetic structure Mp M Berger PRB ’96, Slonczewski JMMM ’96 Ie STT-MRAM

  29. Writing by current: non-relativistic spin-transfer torque Mott with ferromagnets Mott with antiferromagnets Spins injected from external polarizer in a non-uniform magnetic structure Mp M Berger PRB ’96, Slonczewski JMMM ’96 Ie I I I I

  30. Writing by current: relativistic spin-orbit torque Spin current in a uniform magnetic structure without external polarizer M Manchon & Zhang, PRB ‘08, Chernyshev et al. Nature Phys.‘09, Miron et al. Nature Mater. ‘10, Fang, Ferguson, TJ et al. Nature Nanotech.‘11 Ie In-plane current switching Miron et al., Nature ‘11

  31. Writing by current: relativistic spin-orbit torque Spin current in a uniform magnetic structure without external polarizer M Andrew Ferguson, W18.00007 Dirac with ferromagnets Dirac with antiferromagnets Manchon & Zhang, PRB ‘08, Chernyshev et al. Nature Phys.‘09, Miron et al. Nature Mater. ‘10, Fang, Ferguson, TJ et al. Nature Nanotech.‘11 Ie I I I I

  32. Writing by electric field or light: Magnetic semiconductor spintronics Tc < room-T Petr Němec, R18.00001 Ohno, Dietl et al., Science ’98,’00, TJ et al., Rev. Mod. Phys. ‘06 Spintronics & transistors Spintronics &photonics FM semiconductors M

  33. Semiconductors: more AFMs than FMs and high-TN AFMs TJ, Novák, Martí et al. PRB ’11, Cava Viewpoint, Physics ’11, Máca, Mašek, TJ et al. JMMM ’12

  34. Spin-orbit-coupled Mott AFM semiconductor Kim et al., Science ’09, Jin et al. PRB ‘09, Arita et al. PRL ‘12

  35. Ohmic AMR in Sr2IrO4 AFM semiconductor Pt Xavier Martí, T18.00011 SIO SIO Ag Ag Ag LSMO LSMO T = 200 K T = 40 K T = 4.2 K

  36. Metal AFM spintronics B.G. Park, J. Wunderlich, X. Marti, V. Holy, Y. Kurosaki, M. Yamada, H. Yamamoto, A. Nishide, J. Hayakawa, H. Takahashi, A.B. Shick, T. Jungwirth 
 Nature Mater. 10 (2011) 347 – 351 X. Marti, B. G. Park, J. Wunderlich, H. Reichlova, Y. Kurosaki, M. Yamada, H. Yamamoto, A. Nishide, J. Hayakawa, H. Takahashi, T. Jungwirth 

 Phys. Rev. Lett. 108 (2012) 017201(1) - 017201(4) D. Petti, E. Albisetti, H. Reichlová, J. Gazquez, M. Varela, M. Molina-Ruiz, A. F. Lopeandía, K. Olejník, V. Novák, I. Fina, B. Dkhil, J. Hayakawa, X. Marti, J. Wunderlich, T. Jungwirth, R. Bertacco 
 submitted to Appl. Phys. Lett.

  37. Semiconductor AFM spintronics T. Jungwirth, V. Novák, X. Marti, M. Cukr, F. Máca, A.B. Shick, J. Mašek, P. Horodyska, P. Němec, V. Holý, J. Zemek, P. Kužel, I. Němec, B. L. Gallagher, R. P. Campion, C. T. Foxon, J. Wunderlich 

 Phys. Rev. B 83 (2011) 035321(1) - 035321(6). C. Rayan Serrao, Jian Liu, J.T. Heron, G. Singh-Bhalla, A. Yadav, S.J. Suresha, R. J. Paull, D. Yi, J.-H. Chu, M. Trassin, A. Vishwanath, E. Arenholz, C. Frontera, J. Železný, J. Mašek, T. Jungwirth, X. Marti, R. Ramesh 
 Phys. Rev. B 87 (2013) 085121(1)-08512(6) P. Wadley, V. Novak, R. P. Campion, C. Rinaldi, X. Mart, H. Reichlova, J. Zelezny, J. Gazquez, M. A. Roldan, M. Varela, D. Khalyavin, S. Langridge, D. Kriegner,10 F. Maca, J. Masek, V. Holy, A. W. Rushforth, K. W. Edmonds, B. L. Gallagher, C. T. Foxon, J. Wunderlich, and T. Jungwirth, to be published X. Marti, I. Fina, D. Yi, J. Liu, J.H. Chu, C. Rayan-Serrao, S. Suresha, J. Železný, T. Jungwirth, J. Fontcuberta, R. Ramesh, to be published

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