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.

Electronic measurement and control of spin transport in silicon

Abstract

The spin lifetime and diffusion length of electrons are transport parameters that define the scale of coherence in spintronic devices and circuits. As these parameters are many orders of magnitude larger in semiconductors than in metals1,2, semiconductors could be the most suitable for spintronics. So far, spin transport has only been measured in direct-bandgap semiconductors3,4,5,6,7,8,9 or in combination with magnetic semiconductors, excluding a wide range of non-magnetic semiconductors with indirect bandgaps. Most notable in this group is silicon, Si, which (in addition to its market entrenchment in electronics) has long been predicted a superior semiconductor for spintronics with enhanced lifetime and transport length due to low spin–orbit scattering and lattice inversion symmetry10,11,12. Despite this promise, a demonstration of coherent spin transport in Si has remained elusive, because most experiments focused on magnetoresistive devices; these methods fail because of a fundamental impedance mismatch between ferromagnetic metal and semiconductor13, and measurements are obscured by other magnetoelectronic effects14. Here we demonstrate conduction-band spin transport across 10 μm undoped Si in a device that operates by spin-dependent ballistic hot-electron filtering through ferromagnetic thin films for both spin injection and spin detection. As it is not based on magnetoresistance, the hot-electron spin injection and spin detection avoids impedance mismatch issues and prevents interference from parasitic effects. The clean collector current shows independent magnetic and electrical control of spin precession, and thus confirms spin coherent drift in the conduction band of silicon.

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: Illustration of the Si spin transport device.
Figure 2: Simultaneously measured current dependence on tunnel-junction emitter voltage at 85 K.
Figure 3: In-plane magnetic field dependence at 85K.
Figure 4: Spin precession and dephasing in a perpendicular magnetic field at constant emitter voltage V e = -1.8 V and 85 K.

References

  1. 1

    Jedema, F. J., Heersche, H. B., Filip, A. T., Baselmans, J. J. A. & van Wees, B. J. Electrical detection of spin precession in a metallic mesoscopic spin valve. Nature 416, 713– 717 (2002)

    ADS  CAS  Article  Google Scholar 

  2. 2

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

    ADS  CAS  Article  Google Scholar 

  3. 3

    Kikkawa, J. M. & Awschalom, D. D. Resonant spin amplification in n-type GaAs. Phys. Rev. Lett. 80, 4313– 4316 (1998)

    ADS  CAS  Article  Google Scholar 

  4. 4

    Kikkawa, J. M. & Awschalom, D. D. Lateral drag of spin coherence in gallium arsenide. Nature 397, 139– 141 (1999)

    ADS  CAS  Article  Google Scholar 

  5. 5

    Kato, Y., Myers, R. C., Gossard, A. C. & Awschalom, D. D. Coherent spin manipulation without magnetic fields in strained semiconductors. Nature 427, 50– 53 (2003)

    ADS  Article  Google Scholar 

  6. 6

    Stephens, J. et al. Spin accumulation in forward-biased MnAs/GaAs Schottky diodes. Phys. Rev. Lett. 93, 097602 (2004)

    ADS  CAS  Article  Google Scholar 

  7. 7

    Crooker, S. A. et al. Imaging spin transport in lateral ferromagnet/ semiconductor structures. Science 309, 2191– 2195 (2005)

    ADS  CAS  Article  Google Scholar 

  8. 8

    Lou, X. et al. Electrical detection of spin accumulation at a ferromagnet-semiconductor interface. Phys. Rev. Lett. 96, 176603 (2006)

    ADS  CAS  Article  Google Scholar 

  9. 9

    Lou, X. et al. Electrical detection of spin transport in lateral ferromagnet–semiconductor devices. Nature Phys. 3, 197– 202 (2007)

    ADS  CAS  Article  Google Scholar 

  10. 10

    Zutic, I., Fabian, J. & Erwin, S. C. Spin injection and detection in Si. Phys. Rev. Lett. 97, 026602 (2006)

    ADS  Article  Google Scholar 

  11. 11

    Zutic, I., Fabian, J. & Das Sarma, S. Spintronics: Fundamentals and applications. Rev. Mod. Phys. 76, 323– 410 (2004)

    ADS  CAS  Article  Google Scholar 

  12. 12

    Tyryshkin, I. M., Lyon, S. A., Astashkin, A. V. & Raitsimring, A. M. Electron spin relaxation times of phosphorus donors in Si. Phys. Rev. B 68, 193207 (2003)

    ADS  Article  Google Scholar 

  13. 13

    Schmidt, G., Ferrand, D., Molenkamp, L. W., Filip, A. T. & van Wees, B. J. Fundamental obstacle for electrical spin injection from a ferromagnetic metal into a diffusive semiconductor. Phys. Rev. B 62, R4790– R4793 (2000)

    ADS  CAS  Article  Google Scholar 

  14. 14

    Monzon, F. G., Tang, H. X. & Roukes, M. L. Magnetoelectronic phenomena at a ferromagnet-semiconductor interface. Phys. Rev. Lett. 84, 5022– 5022 (2000)

    ADS  CAS  Article  Google Scholar 

  15. 15

    Monsma, D. J., Lodder, J. C., Popma & Dieny, B. Perpendicular hot electron spin-valve effect in a new magnetic field sensor: The spin valve transistor. Phys. Rev. Lett. 74, 5260– 5263 (1995)

    ADS  CAS  Article  Google Scholar 

  16. 16

    Monsma, D. J., Vlutters, R. & Lodder, J. C. Room temperature-operating spin-valve transistors formed by vacuum bonding. Science 281, 407– 409 (1998)

    ADS  CAS  Article  Google Scholar 

  17. 17

    Jiang, X. et al. Optical detection of hot-electron spin injection into GaAs from a magnetic tunnel transistor source. Phys. Rev. Lett. 90, 256603 (2003)

    ADS  CAS  Article  Google Scholar 

  18. 18

    Zega, T. J. et al. Determination of interface atomic structure and its impact on spin transport using Z-contrast microscopy and density-functional theory. Phys. Rev. Lett. 96, 196101 (2006)

    ADS  Article  Google Scholar 

  19. 19

    Johnson, M. & Silsbee, R. H. Interfacial charge-spin coupling: Injection and detection of spin magnetization in metals. Phys. Rev. Lett. 55, 1790– 1793 (1985)

    ADS  CAS  Article  Google Scholar 

  20. 20

    Portis, A. M., Kip, A. F., Kittel, C. & Brattain, W. H. Electron spin resonance in a silicon semiconductor. Phys. Rev. 90, 988– 989 (1953)

    ADS  CAS  Article  Google Scholar 

  21. 21

    Jacoboni, C., Canali, C., Ottaviani, G. & Quaranta, A. A. A review of some charge transport properties of Si. Solid State Electron. 20, 77– 89 (1977)

    ADS  Article  Google Scholar 

  22. 22

    Tyryshkin, A. M., Lyon, S. A., Jantsch, W. & Schäffler, F. Spin manipulation of free two-dimensional electrons in Si/SiGe quantum wells. Phys. Rev. Lett. 94, 126802 (2005)

    ADS  CAS  Article  Google Scholar 

  23. 23

    Jiang, X. et al. Highly spin polarized room temperature tunnel injector for semiconductor spintronics using MgO (100). Phys. Rev. Lett. 94, 056601 (2005)

    ADS  CAS  Article  Google Scholar 

  24. 24

    Smith, D. L. & Silver, R. N. Electrical spin injection into semiconductors. Phys. Rev. B 64, 045323 (2002)

    ADS  Article  Google Scholar 

  25. 25

    Hanbicki, A. T., Jonker, B. T., Itskos, G., Kioseoglou, G. & Petrou, A. Efficient electrical spin injection from a magnetic metal/tunnel barrier contact into a semiconductor. Appl. Phys. Lett. 80, 1240– 1242 (2002)

    ADS  CAS  Article  Google Scholar 

Download references

Acknowledgements

We acknowledge assistance during fabrication from I. Altfeder, SQUID measurements by G. Hadjipanayis and A. Gabay, and use of the wafer saw from K. Goossen. This work is supported by ONR and DARPA/MTO.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Ian Appelbaum.

Ethics declarations

Competing interests

Reprints and permissions information is available at www.nature.com/reprints. The authors declare no competing financial interests.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Appelbaum, I., Huang, B. & Monsma, D. Electronic measurement and control of spin transport in silicon. Nature 447, 295–298 (2007). https://doi.org/10.1038/nature05803

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

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