Electrical spin injection in a ferromagnetic semiconductor heterostructure

Article metrics

Abstract

Conventional electronics is based on the manipulation of electronic charge. An intriguing alternative is the field of ‘spintronics’, wherein the classical manipulation of electronic spin in semiconductor devices gives rise to the possibility of reading and writing non-volatile information through magnetism1,2. Moreover, the ability to preserve coherent spin states in conventional semiconductors3 and quantum dots4 may eventually enable quantum computing in the solid state5,6. Recent studies have shown that optically excited electron spins can retain their coherence over distances exceeding 100 micrometres (ref. 7). But to inject spin-polarized carriers electrically remains a formidable challenge8,9. Here we report the fabrication of all-semiconductor, light-emitting spintronic devices using III–V heterostructures based on gallium arsenide. Electrical spin injection into a non-magnetic semiconductor is achieved (in zero magnetic field) using a p-type ferromagnetic semiconductor10 as the spin polarizer. Spin polarization of the injected holes is determined directly from the polarization of the emitted electroluminescence following the recombination of the holes with the injected (unpolarized) electrons.

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: Electrical spin injection in an epitaxially grown ferromagnetic semiconductor heterostructure, based on GaAs.
Figure 2: Hysteretic electroluminescence polarization is a direct result of spin injection from the ferromagnetic (Ga,Mn)As layer.
Figure 3: The absence of hysteretic polarization.

References

  1. 1

    Awschalom,D. D. & Kikkawa,J. M. Electron spin and optical coherence in semiconductors. Phys. Today 52, 33–38 (1999).

  2. 2

    Prinz,G. A. Magnetoelectronics. Science 282, 1660–1663 (1998).

  3. 3

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

  4. 4

    Gupta,J. A., Awschalom,D. D., Peng,X. & Alivisatos,A. P. Spin coherence in semiconductor quantum dots. Phys. Rev. B 59, 10421–10424 (1999).

  5. 5

    DiVincenzo,D. P. Quantum computation. Science 270, 255–261 (1995).

  6. 6

    Loss,D. & DiVincenzo,D. P. Quantum computation with quantum dots. Phys. Rev. A 57, 120–126 (1998).

  7. 7

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

  8. 8

    Monzon,F. G. & Roukes,M. L. Spin injection and the local hall effect in InAs quantum wells. J. Mag. Magn. Mater. 198, 632–635 (1999).

  9. 9

    Hammar,P. R. et al. Observation of the spin injection at a ferromagnetic-semiconductor interface. Phys. Rev. Lett. 83, 203–206 (1999).

  10. 10

    Ohno,H. Making nonmagnetic semiconductors ferromagnetic. Science 281, 951–955 (1998).

  11. 11

    Ohno,H. et al. (Ga,Mn)As: A new diluted magnetic semiconductor based on GaAs. Appl. Phys. Lett. 69, 363–365 (1996).

  12. 12

    Matsukara,F., Ohno,H., Shen,A. & Sugawara,Y. Transport properties and origin of ferromagnetism in (Ga,Mn)As. Phys. Rev. B 57, 2037–2040 (1998).

  13. 13

    Hägele,D., Oestreich,M., Rühle,W. W., Nestle,N. & Eberl,K. Spin transport in GaAs. Appl. Phys. Lett. 73, 1580–1582 (1998).

  14. 14

    Beschoten,B. et al. Magnetic circular dichroism studies of carrier-induced ferromagnetism in Ga1-xMnxAs. Phys. Rev. Lett. 83, 3073–3076 (1999).

  15. 15

    Van Esch,A. et al. Interplay between the magnetic and transport properties in the III-V diluted magnetic semiconductor Ga1-xMnxAs. Phys. Rev. B 56, 13103–13112 (1997).

  16. 16

    Uenoyama,T. & Sham,L. J. Hole relaxation and luminescence polarization in doped and undoped quantum wells. Phys. Rev. Lett. 64, 3070–3073 (1990).

Download references

Acknowledgements

We thank I. Arata for technical support and D. T. Fuchs and J. M. Kikkawa for critical readings of the manuscript. Work at UCSB is supported by the Air Force Office of Scientific Research, the National Science Foundation through the Center for Quantized Electronic Structures, and the Office of Naval Research. The Japan Society for the Promotion of Science and the Ministry of Education in Japan support work at Tohoku University.

Author information

Correspondence to D. D. Awschalom.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Ohno, Y., Young, D., Beschoten, B. et al. Electrical spin injection in a ferromagnetic semiconductor heterostructure. Nature 402, 790–792 (1999) doi:10.1038/45509

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.