Letter | Published:

Interplay between topological and thermodynamic stability in a metastable magnetic skyrmion lattice

Nature Physics volume 12, pages 6266 (2016) | Download Citation

  • A Corrigendum to this article was published on 03 May 2016

This article has been updated

Abstract

Topologically stable matter can have a long lifetime, even if thermodynamically costly, when the thermal agitation is sufficiently low1,2. A magnetic skyrmion lattice (SkL) represents a unique form of long-range magnetic order that is topologically stable3,4,5,6,7,8,9, such that a long-lived, metastable SkL can form. Experimental observations of the SkL in bulk crystals, however, have mostly been limited to a finite and narrow temperature region in which the SkL is thermodynamically stable5,7,10,11,12,13,14; thus, the benefits of the topological stability remain unclear. Here, we report a metastable SkL created by quenching a thermodynamically stable SkL. Hall-resistivity measurements of MnSi reveal that, although the metastable SkL is short-lived at high temperatures, the lifetime becomes prolonged (1 week) at low temperatures. The manipulation of a delicate balance between thermal agitation and the topological stability enables a deterministic creation/annihilation of the metastable SkL by exploiting electric heating and subsequent rapid cooling, thus establishing a facile method to control the formation of a SkL.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Change history

  • 14 April 2016

    In the version of this Letter originally published the pulse heights in the pulse sequence in Figure 4c were incorrect. This has now been corrected in the online versions of the Letter.

References

  1. 1.

    The topological theory of defects in ordered media. Rev. Mod. Phys. 51, 591–648 (1979).

  2. 2.

    Symmetry defects and broken symmetry. Configurations hidden symmetry. Rev. Mod. Phys. 52, 617–651 (1980).

  3. 3.

    & Thermodynamically stable “vortices” in magnetically ordered crystals. The mixed state of magnets. Sov. Phys. JETP 68, 101–103 (1989).

  4. 4.

    & Thermodynamically stable magnetic vortex states in magnetic crystals. J. Magn. Magn. Mater. 138, 255–269 (1994).

  5. 5.

    et al. Skyrmion lattice in a chiral magnet. Science 323, 915–919 (2009).

  6. 6.

    et al. Skyrmion lattice in the doped semiconductor Fe1−xCoxSi. Phys. Rev. B 81, R041203 (2010).

  7. 7.

    et al. Complex chiral modulations in FeGe close to magnetic ordering. Phys. Rev. Lett. 110, 077207 (2013).

  8. 8.

    et al. Real-space observation of a two-dimensional skyrmion crystal. Nature 465, 901–904 (2010).

  9. 9.

    et al. Near room-temperature formation of a skyrmion crystal in thin-films of the helimagnet FeGe. Nature Mater. 10, 106–109 (2011).

  10. 10.

    et al. Skyrmion lattices in metallic and semiconducting B20 transition metal compounds. J. Phys. Condens. Matter 22, 164207 (2010).

  11. 11.

    et al. Quantum phase transitions in single-crystal Mn1−xFexSi and Mn1−xCoxSi: Crystal growth, magnetization, ac susceptibility, and specific heat. Phys. Rev. B 82, 064404 (2010).

  12. 12.

    , , & Observation of skyrmions in a multiferroic material. Science 336, 198–201 (2012).

  13. 13.

    et al. Real-space and reciprocal-space Berry phases in the Hall effect of Mn1−xFexSi. Phys. Rev. Lett. 112, 186601 (2014).

  14. 14.

    et al. A new class of chiral materials hosting magnetic skyrmions beyond room temperature. Nature Commun. 6, 7638 (2015).

  15. 15.

    et al. The pressure–temperature phase and transformation diagram for carbon; updated through 1994. Carbon 34, 141–153 (1996).

  16. 16.

    , & Applied topological analysis of crystal structures with the program package ToposPro. Cryst. Growth Des. 14, 3576–3586 (2014).

  17. 17.

    et al. Giant generic topological Hall resistivity of MnSi under pressure. Phys. Rev. B 87, 134424 (2013).

  18. 18.

    , , , & Unusual Hall effect anomaly in MnSi under pressure. Phys. Rev. Lett. 102, 186601 (2009).

  19. 19.

    et al. Topological Hall effect in the A phase of MnSi. Phys. Rev. Lett. 102, 186602 (2009).

  20. 20.

    et al. Berry phase theory of the anomalous Hall effect: Application to colossal magnetoresistance manganites. Phys. Rev. Lett. 83, 3737–3740 (1999).

  21. 21.

    , & Topological Hall effect and Berry phase in magnetic nanostructures. Phys. Rev. Lett. 93, 096806 (2004).

  22. 22.

    et al. Unwinding of a Skyrmion lattice by magnetic monopoles. Science 340, 1076–1080 (2013).

  23. 23.

    & Phase-change materials for rewriteable data storage. Nature Mater. 6, 824–832 (2007).

  24. 24.

    Phase change materials. Annu. Rev. Mater. Res. 39, 25–48 (2009).

  25. 25.

    et al. Phase-change memory function of correlated electrons in organic conductors. Phys. Rev. B 91, R041101 (2015).

  26. 26.

    et al. Writing and deleting single magnetic skyrmions. Science 341, 636–639 (2013).

  27. 27.

    , & Current-induced skyrmion dynamics in constricted geometries. Nature Nanotech. 8, 742–747 (2013).

  28. 28.

    , , , & Nucleation, stability and current-induced motion of isolated magnetic skyrmions in nanostructures. Nature Nanotech. 8, 839–844 (2013).

  29. 29.

    et al. Memory functions of magnetic skyrmions. Jpn. J. Appl. Phys. 54, 053001 (2015).

  30. 30.

    , , , & Field-dependent size and shape of single magnetic skyrmions. Phys. Rev. Lett. 114, 177203 (2015).

Download references

Acknowledgements

We thank N. Nagaosa, W. Koshibae and A. Rosch for fruitful discussions. This work was partially supported by JSPS KAKENHI (Grant Nos. 25220709, 24224009, 15H05459).

Author information

Affiliations

  1. RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan

    • Hiroshi Oike
    • , Akiko Kikkawa
    • , Yasujiro Taguchi
    • , Masashi Kawasaki
    • , Yoshinori Tokura
    •  & Fumitaka Kagawa
  2. Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan

    • Naoya Kanazawa
    • , Masashi Kawasaki
    •  & Yoshinori Tokura
  3. CREST, Japan Science and Technology Agency (JST), Tokyo 102-0076, Japan

    • Fumitaka Kagawa

Authors

  1. Search for Hiroshi Oike in:

  2. Search for Akiko Kikkawa in:

  3. Search for Naoya Kanazawa in:

  4. Search for Yasujiro Taguchi in:

  5. Search for Masashi Kawasaki in:

  6. Search for Yoshinori Tokura in:

  7. Search for Fumitaka Kagawa in:

Contributions

H.O. conducted all experiments and analysed the data. A.K. grew the single crystals used for the study. F.K. planned and supervised the project. H.O. and F.K. wrote the letter. All authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Fumitaka Kagawa.

Supplementary information

PDF files

  1. 1.

    Supplementary information

    Supplementary information

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nphys3506

Further reading