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.

Confluence of resonant laser excitation and bidirectional quantum-dot nuclear-spin polarization

Abstract

Resonant laser scattering along with photon correlation measurements established the atom-like character of quantum dots. Here, we show that for a wide range of experimental parameters it is impossible to isolate elementary quantum-dot excitations from a strong influence of nuclear spins; the absorption lineshapes at magnetic fields exceeding 1 T indicate that the nuclear spins get polarized by an amount that ensures locking of the quantum-dot resonance to the incident laser frequency. In stark contrast to earlier experiments, this nuclear-spin polarization is bidirectional, allowing the combined electron–nuclear-spin system to track the changes in laser frequency dynamically on both sides of the resonance. This unexpected feature stems from a competition between two spin-pumping processes that attempt to polarize nuclear spins in opposite directions. We find that the confluence of laser excitation and nuclear-spin polarization suppresses the fluctuations in resonant absorption. A master-equation analysis suggests narrowing of the nuclear-spin distribution, pointing to applications in quantum information processing.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Dragging of quantum-dot resonances.
Figure 2: Dependence of dragging on system parameters.
Figure 3: Bidirectional nuclear-spin polarization.
Figure 4: Suppression of fluctuations in quantum-dot resonance frequency.

References

  1. Michler, P. et al. A quantum dot single-photon turnstile device. Science 290, 2282–2285 (2000).

    Article  ADS  Google Scholar 

  2. Högele, A. et al. Voltage-controlled optics of a quantum dot. Phys. Rev. Lett. 93, 217401 (2004).

    Article  ADS  Google Scholar 

  3. Petta, J. R. et al. Coherent manipulation of coupled electron spins in semiconductor quantum dots. Science 309, 2180–2184 (2005).

    Article  ADS  Google Scholar 

  4. Braun, P. F. et al. Direct observation of the electron spin relaxation induced by nuclei in quantum dot. Phys. Rev. Lett. 94, 116601 (2005).

    Article  ADS  Google Scholar 

  5. Khaetskii, A., Loss, D. & Glazman, L. Electron spin decoherence in quantum dots due to interaction with nuclei. Phys. Rev. Lett. 88, 186802 (2002).

    Article  ADS  Google Scholar 

  6. Gammon, D. et al. Electron and nuclear spin interactions in the optical spectra of single GaAs quantum dots. Phys. Rev. Lett. 86, 5176–5179 (2001).

    Article  ADS  Google Scholar 

  7. Eble, B. et al. Dynamic nuclear polarization of a single charge-tunable InAs/GaAs quantum dot. Phys. Rev. B 74, 081306 (2006).

    Article  ADS  Google Scholar 

  8. Koppens, F. H. L. et al. Driven coherent oscillations of a single electron spin in a quantum dot. Nature 442, 766–771 (2006).

    Article  ADS  Google Scholar 

  9. Lai, C. W., Maletinsky, P., Badolato, A. & Imamoglu, A. Knight-field-enabled nuclear spin polarization in single quantum dots. Phys. Rev. Lett. 96, 167403 (2006).

    Article  ADS  Google Scholar 

  10. Maletinsky, P. et al. Nonlinear dynamics of quantum dot nuclear spins. Phys. Rev. B 75, 035409 (2007).

    Article  ADS  Google Scholar 

  11. Tartakovskii, A. et al. Nuclear spin switch in semiconductor quantum dots. Phys. Rev. Lett. 98, 026806 (2007).

    Article  ADS  Google Scholar 

  12. Reilly, D. et al. Suppressing spin qubit dephasing by nuclear state preparation. Science 321, 817–821 (2008).

    Article  ADS  Google Scholar 

  13. Smith, J. M. et al. Voltage control of the spin dynamics of an exciton in a semiconductor quantum dot. Phys. Rev. Lett. 94, 197402 (2005).

    Article  ADS  Google Scholar 

  14. Maletinsky, P. et al. Dynamics of quantum dot nuclear spin polarization controlled by a single electron. Phys. Rev. Lett. 99, 056804 (2007).

    Article  ADS  Google Scholar 

  15. Atatüre, M. et al. Quantum-dot spin-state preparation with near-unity fidelity. Science 312, 551–553 (2006).

    Article  ADS  Google Scholar 

  16. Bayer, M. et al. Electron and hole g factors and exchange interaction from studies of the exciton fine structure in In0.60Ga0.40As quantum dots. Phys. Rev. Lett. 82, 1748–1751 (1999).

    Article  ADS  Google Scholar 

  17. Dreiser, J. et al. Optical investigations of quantum dot spin dynamics as a function of external electric and magnetic fields. Phys. Rev. B 77, 075317 (2008).

    Article  ADS  Google Scholar 

  18. Maletinsky, P., Kroner, M. & Imamoglu, A. Breakdown of the nuclear spin temperature approach in quantum dot demagnetization experiments. Nature Phys. 5, 407–411 (2009).

    Article  ADS  Google Scholar 

  19. Vink, I. T. et al. Locking electron spins into magnetic resonance by electron-nuclear feedback. Nature Phys.doi:10.1038/nphys1366 (2009).

    Article  ADS  Google Scholar 

  20. Rudner, M. & Levitov, L. Electrically driven reverse Overhauser pumping of nuclear spins in quantum dots. Phys. Rev. Lett. 99, 246602 (2007).

    Article  ADS  Google Scholar 

  21. Danon, J. & Nazarov, Y. V. Nuclear tuning and detuning of the electron spin resonance in a quantum dot: Theoretical consideration. Phys. Rev. Lett. 100, 056603 (2008).

    Article  ADS  Google Scholar 

  22. Greilich, A. et al. Mode locking of electron spin coherences in singly charged quantum dots. Science 313, 341–345 (2006).

    Article  ADS  Google Scholar 

  23. Coish, W. A. & Loss, D. Hyperfine interaction in a quantum dot: Non-Markovian electron spin dynamics. Phys. Rev. B 70, 195340 (2004).

    Article  ADS  Google Scholar 

  24. Taylor, J. M. et al. Relaxation, dephasing, and quantum control of electron spins in double quantum dots. Phys. Rev. B 76, 035315 (2007).

    Article  ADS  Google Scholar 

  25. Cywinski, L., Witzel, W. M. & Das Sarma, S. Electron spin dephasing due to hyperfine interactions with a nuclear spin bath. Phys. Rev. Lett. 102, 057601 (2009).

    Article  ADS  Google Scholar 

  26. Taylor, J. M., Imamoglu, A. & Lukin, M. D. Controlling a mesoscopic spin environment by quantum bit manipulation. Phys. Rev. Lett. 91, 246802 (2003).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We thank S. Fält for growing samples B and C. We also acknowledge many useful discussions with H. Türeci, J. Taylor, G. Giedke, M. Rudner and L. Levitov. This work was supported by NCCR Quantum Photonics (NCCR QP), research instruments of the Swiss National Science Foundation (SNSF), and by an ERC Advanced Investigator Grant (A.I.). The work carried out in Cambridge was supported by QIP IRC and EPSRC grant No EP/G000883/1. D.S. and W.W. would like to thank the Deutsche Forschungsgemeinschaft (DFG) and the Bundesministerium fuer Bildung und Forschung (BMBF) for financial support.

Author information

Authors and Affiliations

Authors

Contributions

C.L. and A.H. carried out the experiments on samples A and C. Y.Z. and A.N.V. carried out the experiments on sample B. A.B., D.S. and W.W. grew the samples. A.I., along with C.L. and A.H., developed the model that explained the experimental observations. C.L., I.C. and A.I. did the theoretical analysis. P.M., M.K., J.D. and M.A. carried out earlier experiments and actively participated in discussions. A.H., M.A. and A.I. planned the experiments.

Corresponding author

Correspondence to A. Imamoglu.

Supplementary information

Supplementary Information

Supplementary Information (PDF 402 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Latta, C., Högele, A., Zhao, Y. et al. Confluence of resonant laser excitation and bidirectional quantum-dot nuclear-spin polarization. Nature Phys 5, 758–763 (2009). https://doi.org/10.1038/nphys1363

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nphys1363

This article is cited by

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