Giant spin Seebeck effect in a non-magnetic material

Abstract

The spin Seebeck effect is observed when a thermal gradient applied to a spin-polarized material leads to a spatially varying transverse spin current in an adjacent non-spin-polarized material, where it gets converted into a measurable voltage. It has been previously observed with a magnitude of microvolts per kelvin in magnetically ordered materials, ferromagnetic metals1, semiconductors2 and insulators3. Here we describe a signal in a non-magnetic semiconductor (InSb) that has the hallmarks of being produced by the spin Seebeck effect, but is three orders of magnitude larger (millivolts per kelvin). We refer to the phenomenon that produces it as the giant spin Seebeck effect. Quantizing magnetic fields spin-polarize conduction electrons in semiconductors by means of Zeeman splitting, which spin–orbit coupling amplifies by a factor of 25 in InSb. We propose that the giant spin Seebeck effect is mediated by phonon–electron drag, which changes the electrons’ momentum and directly modifies the spin-splitting energy through spin–orbit interactions. Owing to the simultaneously strong phonon–electron drag and spin–orbit coupling in InSb, the magnitude of the giant spin Seebeck voltage is comparable to the largest known classical thermopower values.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Detection scheme for measurement of the SSE in non-magnetic InSb.
Figure 2: Experimental data on the SSE in InSb.
Figure 3: Classical thermomagnetic properties of InSb.
Figure 4: How phonon–electron drag causes the SSE in InSb through the spin-orbit interaction.

References

  1. 1

    Uchida, K. et al. Observation of the spin Seebeck effect. Nature 455, 778–781 (2008)

    ADS  CAS  Article  Google Scholar 

  2. 2

    Jaworski, C. M. et al. Observation of the spin-Seebeck effect in a ferromagnetic semiconductor. Nature Mater. 9, 898–903 (2010)

    ADS  CAS  Article  Google Scholar 

  3. 3

    Uchida, K. et al. Spin Seebeck insulator. Nature Mater. 9, 894–897 (2010)

    ADS  CAS  Article  Google Scholar 

  4. 4

    Jaworski, C. M. et al. Spin-Seebeck effect: a phonon driven spin distribution. Phys. Rev. Lett. 106, 186601 (2011)

    ADS  CAS  Article  Google Scholar 

  5. 5

    Adachi, H. et al. Gigantic enhancement of spin Seebeck effect by phonon drag. Appl. Phys. Lett. 97, 252506 (2010)

    ADS  Article  Google Scholar 

  6. 6

    Adachi, H. et al. Linear-response theory of spin Seebeck effect in ferromagnetic insulators. Phys. Rev. B 83, 094410 (2011)

    ADS  Article  Google Scholar 

  7. 7

    Tserkovnyak, Y. et al. Spin pumping and magnetization dynamics in metallic multilayers. Phys. Rev. B 66, 224403 (2002)

    ADS  Article  Google Scholar 

  8. 8

    Xiao, J. et al. Theory of magnon-driven spin Seebeck effect. Phys. Rev. B 81, 214418 (2010)

    ADS  Article  Google Scholar 

  9. 9

    Valenzuela, S. O. & Tinkham, M. Direct electronic measurement of the spin Hall effect. Nature 442, 176–179 (2006)

    ADS  CAS  Article  Google Scholar 

  10. 10

    Yu, H. et al. Evidence for thermal spin-transfer torque. Phys. Rev. Lett. 104, 146601 (2010)

    ADS  Article  Google Scholar 

  11. 11

    Le Breton, J.-C. et al. Thermal spin current from a ferromagnet to silicon by Seebeck spin tunnelling. Nature 475, 82–85 (2011)

    ADS  CAS  Article  Google Scholar 

  12. 12

    Uchida, K. et al. Observation of the longitudinal spin-Seebeck effect in magnetic insulators. Appl. Phys. Lett. 97, 172505 (2010)

    ADS  Article  Google Scholar 

  13. 13

    Weiler, M. et al. Local charge and spin currents in magnetothermal landscapes. Phys. Rev. Lett. 108, 106602 (2012)

    ADS  Article  Google Scholar 

  14. 14

    Saitoh, E. et al. Conversion of spin current into charge current at room temperature: inverse spin-Hall effect. Appl. Phys. Lett. 88, 182509 (2006)

    ADS  Article  Google Scholar 

  15. 15

    Madelung, O. Landolt-Börnstein. Numerical Data and Functional Relationships in Science and Technology New Series Group III, Vol. 17, Subvol. A, section 2.15 (Springer, 1982)

  16. 16

    Shoenberg, D. Magnetic Oscillations in Metals (Cambridge Univ. Press, 1984)

    Google Scholar 

  17. 17

    Puri, S. M. & Geballe, T. H. Phonon drag in n-type InSb. Phys. Rev. 136, A1767–A1774 (1964)

    ADS  Article  Google Scholar 

  18. 18

    Dresselhaus, G. Spin-orbit coupling effects in zinc blende structures. Phys. Rev. 100, 580–586 (1955)

    ADS  CAS  Article  Google Scholar 

  19. 19

    Bosu, S. et al. Spin Seebeck effect in thin films of the Heusler compound Co2MnSi. Phys. Rev. B 83, 224401 (2011)

    ADS  Article  Google Scholar 

Download references

Acknowledgements

We thank Y. Kato, H. Adachi, S. Maekawa and D. Stroud for discussions, and K. Wickey for assistance. This work was supported by the NSF CBET-1133589 (data acquisition and interpretation) and by DMR-0820414 (sample preparation). C.M.J. has a fellowship from the DOE GATE Center of Excellence FG26 05NT42616.

Author information

Affiliations

Authors

Contributions

C.M.J., R.C.M. and J.P.H. conceived the study; C.M.J. designed the experiments, prepared the samples with help from E.J.-H., and collected and carried out analysis of the data. R.C.M. and J.P.H. developed the explanation. All authors discussed the results and participated in writing the manuscript.

Corresponding author

Correspondence to J. P. Heremans.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Text and Data, Supplementary Figures 1-7 and Supplementary References. (PDF 1503 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Jaworski, C., Myers, R., Johnston-Halperin, E. et al. Giant spin Seebeck effect in a non-magnetic material. Nature 487, 210–213 (2012). https://doi.org/10.1038/nature11221

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing