Ferroelectrically tunable magnetic skyrmions in ultrathin oxide heterostructures
Source abstract
Abstract
Magnetic skyrmions are topologically protected whirling spin texture. Their nanoscale dimensions, topologically protected stability and solitonic nature, together are promising for future spintronics applications. To translate these compelling features into practical spintronic devices, a key challenge lies in achieving effective control of skyrmion properties, such as size, density and thermodynamic stability. Here, we report the discovery of ferroelectrically tunable skyrmions in ultrathin BaTiO3/SrRuO3 bilayer heterostructures. The ferroelectric proximity effect at the BaTiO3/SrRuO3 heterointerface triggers a sizeable Dzyaloshinskii-Moriya interaction, thus stabilizing robust skyrmions with diameters less than a hundred nanometres. Moreover, by manipulating the ferroelectric polarization of the BaTiO3 layer, we achieve local, switchable and nonvolatile control of both skyrmion density and thermodynamic stability. This ferroelectrically tunable skyrmion system can simultaneously enhance the integratability and addressability of skyrmion-based functional devices.
Source: europepmc · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Ferroelectric and Piezoelectric Materials · Multiferroics and related materials · Electronic and Structural Properties of Oxides
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (53)
Show source-provided references
1. Nagaosa, N. & Tokura, Y. Topological properties and dynamics of magnetic skyrmions. Nat. Nanotech. 8, 899–911 (2013).10.1038/nnano.2013.243 ↗
2. Fert, A., Reyren, N. & Cros, V. Magnetic skyrmions: advances in physics and potential applications. Nat. Rev. Mater. 2, 17031 (2017).10.1038/natrevmats.2017.31 ↗
3. Mühlbauer, S. et al. Skyrmion lattice in a chiral magnet. Science 323, 915–919 (2009).10.1126/science.1166767 ↗
4. Sampaio, J., Cros, V., Rohart, S., Thiaville, A. & Fert, A. Nucleation, stability and current-induced motion of isolated magnetic skyrmions in nanostructures. Nat. Nanotech. 8, 839–844 (2013).10.1038/nnano.2013.210 ↗
5. Hagemeister, J., Romming, N., Von Bergmann, K., Vedmedenko, E. Y. & Wiesendanger, R. Stability of single skyrmionic bits. Nat. Commun. 6, 8455 (2015).10.1038/ncomms9455 ↗
6. Yu, X. Z. et al. Real-space observation of a two-dimensional skyrmion crystal. Nature 465, 901–904 (2010).10.1038/nature09124 ↗
7. Heinze, S. et al. Spontaneous atomic-scale magnetic skyrmion lattice in two dimensions. Nat. Phys. 7, 713–718 (2011).10.1038/nphys2045 ↗
8. Milde, P. et al. Unwinding of a skyrmion lattice by magnetic monopoles. Science 340, 1076–1081 (2013).10.1126/science.1234657 ↗
9. Jiang, W. et al. Blowing magnetic skyrmion bubbles. Science 349, 283–286 (2015).10.1126/science.aaa1442 ↗
10. Woo, S. et al. Observation of room-temperature magnetic skyrmions and their current-driven dynamics in ultrathin metallic ferromagnets. Nat. Mater. 15, 501–506 (2016).10.1038/nmat4593 ↗
11. Büttner, F. et al. Field-free deterministic ultrafast creation of magnetic skyrmions by spin–orbit torques. Nat. Nanotech. 12, 1040–1044 (2017).10.1038/nnano.2017.178 ↗
12. Romming, N. et al. Writing and deleting single magnetic skyrmions. Science 341, 636–639 (2013).10.1126/science.1240573 ↗
13. Fert, A., Cros, V. & Sampaio, J. Skyrmions on the track. Nat. Nanotech. 8, 152–156 (2013).10.1038/nnano.2013.29 ↗
14. Röβler, U. K., Bogdanov, A. N. & Pfleiderer, C. Spontaneous skyrmion ground states in magnetic metals. Nature 442, 797–801 (2006).10.1038/nature05056 ↗
15. Dzyaloshinsky, I. A thermodynamic theory of ‘weak’ ferromagnetism of antiferromagnetics. J. Phys. Chem. Solids. 4, 241–255 (1958).10.1016/0022-3697(58)90076-3 ↗
16. Moriya, T. Anisotropic superexchange interaction and weak ferromagnetism. Phys. Rev. 120, 91–98 (1960).10.1103/PhysRev.120.91 ↗
17. Siemens, A., Zhang, Y., Hagemeister, J., Vedmedenko, E. Y. & Wiesendanger, R. Minimal radius of magnetic skyrmions: statics and dynamics. New J. Phys. 18, 045021 (2016).10.1088/1367-2630/18/4/045021 ↗
18. Seki, S. et al. Observation of skyrmions in a multiferroic material. Science 336, 198–201 (2012).10.1126/science.1214143 ↗
19. Kezsmarki, I. et al. Néel-type skyrmion lattice with confined orientation in the polar magnetic semiconductor GaV4S8. Nat. Mater. 14, 1116–1122 (2015).10.1038/nmat4402 ↗
20. Moreau-Luchaire, C. et al. Additive interfacial chiral interaction in multilayers for stabilization of small individual skyrmions at room temperature. Nat. Nanotech. 11, 444–448 (2016).10.1038/nnano.2015.313 ↗
21. Soumyanarayanan, A. et al. Tunable room temperature magnetic skyrmions in Ir/Fe/Co/Pt multilayers. Nat. Mater. 16, 898–904 (2017).10.1038/nmat4934 ↗
22. Schott, M. et al. The skyrmion switch: Turning magnetic skyrmion bubbles on and off with an electric field. Nano. Lett. 17, 3006–3012 (2017).10.1021/acs.nanolett.7b00328 ↗
23. Maccariello, D. et al. Electrical detection of single magnetic skyrmion at room temperature. Nat. Nanotech. 13, 233–237 (2018).10.1038/s41565-017-0044-4 ↗
24. Ohuchi, Y. et al. Electric-field control of anomalous and topological Hall effects in oxide bilayer thin films. Nat. Commun. 9, 213 (2018).10.1038/s41467-017-02629-3 ↗
25. Hsu, P. J. et al. Electric-field-driven switching of individual magnetic skyrmions. Nat. Nanotech. 12, 123–126 (2017).10.1038/nnano.2016.234 ↗
26. Cheong, S. W. & Mostovoy, M. Multiferroics: A magnetic twist for ferroelectricity. Nat. Mater. 6, 13–20 (2007).10.1038/nmat1804 ↗
27. Ruff, E. et al. Multiferroicity and skyrmions carrying electric polarization in GaV4S8. Sci. Adv. 1, e1500916 (2015).10.1126/sciadv.1500916 ↗
28. Chakraverty, S. et al. Multiple helimagnetic phases and topological Hall effect in epitaxial thin films of pristine and Co-doped SrFeO3. Phys. Rev. B 88, 220405(R) (2013).10.1103/PhysRevB.88.220405 ↗
29. Ahadi, K., Galletti, L. & Stemmer, S. Evidence of a topological Hall effect in Eu1−xSmxTiO3. Appl. Phys. Lett. 111, 172403 (2017).10.1063/1.4997498 ↗
30. Matsuno, J. et al. Interface-driven topological Hall effect in SrRuO3−SrIrO3 bilayer. Sci. Adv. 2, e1600304 (2016).10.1126/sciadv.1600304 ↗
31. Hwang, H. Y. et al. Emergent phenomena at oxide interfaces. Nat. Mater. 11, 103–113 (2012).10.1038/nmat3223 ↗
32. Gerra, G., Tagantsev, A. K., Setter, N. & Parlinski, K. Ionic polarizability of conductive metal oxides and critical thickness for ferroelectricity in BaTiO3. Phys. Rev. Lett. 96, 107603 (2006).10.1103/PhysRevLett.96.107603 ↗
33. Chisholm, M. F., Luo, W., Oxley, M. P., Pantelides, S. T. & Lee, H. N. Atomic-scale compensation phenomena at polar interfaces. Phys. Rev. Lett. 105, 197602 (2010).10.1103/PhysRevLett.105.197602 ↗
34. Shin, Y. J. et al. Interface control of ferroelectricity in an SrRuO3/BaTiO3/SrRuO3 capacitor and its critical thickness. Adv. Mater. 29, 1602795 (2017).10.1002/adma.201602795 ↗
35. Guo, H. et al. Interface-induced multiferroism by design in complex oxide superlattices. Proc. Natl Acad. Sci. 114, E5062–E5069 (2017).
36. Mattheiss, L. F. Electronic structure of RuO2, OsO2, and IrO2. Phys. Rev. B 13, 2433–2450 (1976).10.1103/PhysRevB.13.2433 ↗
37. Kwei, G. H., Lawson, A. C., Billinge, S. J. L. & Cheong, S. W. Structures of the ferroelectric phases of barium titanate. J. Phys. Chem. 97, 2368–2377 (1993).10.1021/j100112a043 ↗
38. Wang, L. et al. Electronic-reconstruction-enhanced-tunneling conductance at terrace edges of ultrathin oxide films. Adv. Mater. 29, 1702001 (2017).10.1002/adma.201702001 ↗
39. Koster, G. et al. Structure, physical properties, and applications of SrRuO3 thin films. Rev. Mod. Phys. 84, 253–298 (2012).10.1103/RevModPhys.84.253 ↗
40. Yu, X., Tokunaga, Y., Taguchi, Y. & Tokura, Y. Variation of topology in magnetic bubbles in a colossal magnetoresistive manganite. Adv. Mater. 29, 1603958 (2017).10.1002/adma.201603958 ↗
41. Pollard, S. D. et al. Observation of stable Néel skyrmions in cobalt/palladium multilayers with Lorentz transmission electron microscopy. Nat. Commun. 8, 14761 (2017).10.1038/ncomms14761 ↗
42. Yagil, A. et al. Stray field signatures of Néel textured skyrmions in Ir/Fe/Co/Pt multilayer films. Appl. Phys. Lett. 112, 192403 (2018).10.1063/1.5027602 ↗
43. Nakazawa, K., Bibes, M. & Kohno, H. Topological Hall effect from strong to weak coupling. J. Phys. Soc. Japan 87, 033705 (2018).10.7566/JPSJ.87.033705 ↗
44. Ahn, C. H., Rabe, K. M. & Triscone, J.-M. Ferroelectricity at the nanoscale: local polarization in oxide thin films and heterostructures. Science 303, 488–491 (2004).10.1126/science.1092508 ↗
45. Cen, C. et al. Nanoscale control of an interfacial metal–insulator transition at room temperature. Nat. Mater. 7, 298–302 (2008).10.1038/nmat2136 ↗
46. Liu, X., Tsymbal, E. Y. & Rabe, K. M. Polarization-controlled modulation doping of a ferroelectric from first principles. Phys. Rev. B 97, 094107 (2018).10.1103/PhysRevB.97.094107 ↗
47. Ahn, C. H. et al. Electrostatic modification of novel materials. Rev. Mod. Phys. 78, 1185–1212 (2006).10.1103/RevModPhys.78.1185 ↗
48. Dawber, M., Rabe, K. M. & Scott, J. F. Physics of thin-film ferroelectric oxides. Rev. Mod. Phys. 77, 1083–1130 (2005).10.1103/RevModPhys.77.1083 ↗
49. Kresse, G. & Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. Rev. B 54, 11169–11186 (1996).10.1103/PhysRevB.54.11169 ↗
50. Xiang, H. J., Kan, E. J., Wei, S. H., Whangbo, M.-H. & Gong, X. G. Predicting the spin-lattice order of frustrated systems from first principles. Phys. Rev. B 84, 224429 (2011).10.1103/PhysRevB.84.224429 ↗
51. Yang, H., Thiaville, A., Rohart, S., Fert, A. & Chshiev, M. Anatomy of Dzyaloshinskii–Moriya interaction at Co/Pt interfaces. Phys. Rev. Lett. 115, 267210 (2015).10.1103/PhysRevLett.115.267210 ↗
52. Perdew, J. P., Burke, K. & Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 77, 3865–3868 (1996).10.1103/PhysRevLett.77.3865 ↗
53. Zhou, H. et al. Evolution and control of the phase competition morphology in a manganite film. Nat. Commun. 6, 8980 (2015).10.1038/ncomms9980 ↗