Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Control of the millisecond spin lifetime of an electrically probed atom

Abstract

Electrical control and readout of magnetic states is an important goal in spintronics. But electrical access to quantum spin systems comes at the cost of coupling to electrodes, which reduces the spin lifetimes through relaxation to electron–hole pairs. Here we report an electrically probed single-atom spin that is long-lived thanks to engineering the coupling of individual iron atoms to the nearby metallic electrodes. Using spin-polarized scanning tunnelling microscopy, we show that the excited spin state of these atoms persists for more than ten milliseconds. The lifetime can be tuned by varying the distance to the microscope probe tip—acting as one electrode—and by changing the thickness of the insulating film which separates the atom from the underlying electrode. The cross-section for spin-flip scattering is so small that many thousands of electrons can probe the spin state projectively before it relaxes. Using all-electrical pump–probe spectroscopy, we measure the lifetime of the atom for different tip–atom distances and determine the intrinsic lifetime as a function of the insulator thickness. We explain the tuning of the spin lifetime in terms of the conductance to each of the electrodes, which provides a method to maximize the electrical readout signal for a given lifetime.

This is a preview of subscription content

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: Spin-polarized readout of single-atom Fe spins on a surface.
Figure 2: Control of the spin lifetime with STM tip proximity.
Figure 3: Spin lifetime as a function of applied magnetic field.
Figure 4: Tuning the substrate conductance and lifetime by film thickness.

References

  1. 1

    Chappert, C., Fert, A. & Van Dau, F. N. The emergence of spin electronics in data storage. Nat. Mater. 6, 813–823 (2007).

    ADS  Article  Google Scholar 

  2. 2

    Khajetoorians, A. A. et al. Current-driven spin dynamics of artificially constructed quantum magnets. Science 339, 55–59 (2013).

    ADS  Article  Google Scholar 

  3. 3

    Sessoli, R., Gatteschi, D., Caneschi, A. & Novak, M. A. Magnetic bistability in a metal-ion cluster. Nature 365, 141–143 (1993).

    ADS  Article  Google Scholar 

  4. 4

    Gatteschi, D., Sessoli, R. & Villain, J. Molecular Nanomagnets (Oxford Univ. Press, 2006).

    Book  Google Scholar 

  5. 5

    Thomas, L. et al. Macroscopic quantum tunnelling of magnetization in a single crystal of nanomagnets. Nature 383, 145–147 (1996).

    ADS  Article  Google Scholar 

  6. 6

    Gatteschi, D. & Sessoli, R. Quantum tunneling of magnetization and related phenomena in molecular materials. Angew. Chem. Int. Ed. 42, 268–297 (2003).

    Article  Google Scholar 

  7. 7

    Brune, H. & Gambardella, P. Magnetism of individual atoms adsorbed on surfaces. Surf. Sci. 603, 1812–1830 (2009).

    ADS  Article  Google Scholar 

  8. 8

    Wiesendanger, R. Spin mapping at the nanoscale and atomic scale. Rev. Mod. Phys. 81, 1495–1550 (2009).

    ADS  Article  Google Scholar 

  9. 9

    Khajetoorians, A. A. et al. Itinerant nature of atom-magnetization excitation by tunneling electrons. Phys. Rev. Lett. 106, 037205 (2011).

    ADS  Article  Google Scholar 

  10. 10

    Khajetoorians, A. A. et al. Spin excitations of individual Fe atoms on Pt(111): impact of the site-dependent giant substrate polarization. Phys. Rev. Lett. 111, 157204 (2013).

    ADS  Article  Google Scholar 

  11. 11

    Heinrich, B. W., Braun, L., Pascual, J. I. & Franke, K. J. Protection of excited spin states by a superconducting energy gap. Nat. Phys. 9, 765–768 (2013).

    Article  Google Scholar 

  12. 12

    Loth, S., Etzkorn, M., Lutz, C. P., Eigler, D. M. & Heinrich, A. J. Measurement of fast electron spin relaxation times with atomic resolution. Science 329, 1628–1630 (2010).

    ADS  Article  Google Scholar 

  13. 13

    Rau, I. G. et al. Reaching the magnetic anisotropy limit of a 3d metal atom. Science 344, 988–992 (2014).

    ADS  Article  Google Scholar 

  14. 14

    Donati, F. et al. Magnetic remanence in single atoms. Science 352, 318–321 (2016).

    ADS  Article  Google Scholar 

  15. 15

    Steinbrecher, M. et al. Absence of a spin-signature from a single Ho adatom as probed by spin-sensitive tunneling. Nat. Commun. 7, 10454 (2016).

    ADS  Article  Google Scholar 

  16. 16

    Coffey, D. et al. Antiferromagnetic spin coupling between rare earth adatoms and iron islands probed by spin-polarized tunneling. Sci. Rep. 5, 13709 (2015).

    ADS  Article  Google Scholar 

  17. 17

    Loth, S., Lutz, C. P. & Heinrich, A. J. Spin-polarized spin excitation spectroscopy. New J. Phys. 12, 125021 (2010).

    ADS  Article  Google Scholar 

  18. 18

    Baumann, S. et al. Electron paramagnetic resonance of individual atoms on a surface. Science 350, 417–420 (2015).

    ADS  Article  Google Scholar 

  19. 19

    Baumann, S. et al. Origin of perpendicular magnetic anisotropy and large orbital moment in Fe atoms on MgO. Phys. Rev. Lett. 115, 237202 (2015).

    ADS  Article  Google Scholar 

  20. 20

    Gauyacq, J.-P., Lorente, N. & Novaes, F. D. Excitation of local magnetic moments by tunneling electrons. Prog. Surf. Sci. 87, 63–107 (2012).

    ADS  Article  Google Scholar 

  21. 21

    Delgado, F. & Fernández-Rossier, J. Spin dynamics of current-driven single magnetic adatoms and molecules. Phys. Rev. B 82, 134414 (2010).

    ADS  Article  Google Scholar 

  22. 22

    Lambe, J. & Jaklevic, R. Molecular vibration spectra by inelastic electron tunneling. Phys. Rev. 165, 821–832 (1968).

    ADS  Article  Google Scholar 

  23. 23

    Freedman, D. E. et al. Slow magnetic relaxation in a high-spin iron(II) complex. J. Am. Chem. Soc. 132, 1224–1225 (2010).

    Article  Google Scholar 

  24. 24

    Kramers, H. A. Théorie générale de la rotation paramagnétique dans les cristaux. Proc. Acad. Sci. Amsterdam 33, 959–972 (1930).

    MATH  Google Scholar 

  25. 25

    Steurer, W., Gross, L. & Meyer, G. Local thickness determination of thin insulator films via localized states. Appl. Phys. Lett. 104, 231606 (2014).

    ADS  Article  Google Scholar 

  26. 26

    Agraït, N., Levy Yeyati, A. & van Ruitenbeek, J. M. Quantum properties of atomic-sized conductors. Phys. Rep. 377, 81–279 (2003).

    ADS  Article  Google Scholar 

Download references

Acknowledgements

We thank B. Melior for expert technical assistance, A. Macdonald, S. Rolf-Pissarczyk and R. M. Macfarlane for helpful discussions, and P. Willke, F. Natterer and T. Greber for providing comments on the manuscript. We gratefully acknowledge financial support from the Office of Naval Research. N.R. acknowledges financial support from the German Academic Exchange Service (DAAD). K.Y. acknowledges support from the National Natural Science Foundation of China (Grant No. 61471337). W.P. thanks the Natural Sciences and Engineering Research Council of Canada for fellowship support.

Author information

Affiliations

Authors

Contributions

W.P., K.Y., S.B., C.P.L. and A.J.H. designed the experiment. W.P., K.Y., S.B. and N.R. carried out the STM measurements. W.P. and K.Y. performed the analysis, W.P. and C.P.L. designed and implemented the pump–probe protocols, C.P.L. and W.P. developed the model, and W.P. carried out the calculations. W.P. and C.P.L. wrote the manuscript. All authors discussed the results and edited the manuscript.

Corresponding author

Correspondence to William Paul.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 1820 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Paul, W., Yang, K., Baumann, S. et al. Control of the millisecond spin lifetime of an electrically probed atom. Nature Phys 13, 403–407 (2017). https://doi.org/10.1038/nphys3965

Download citation

Further reading

Search

Quick links

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