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Observation of spin-dependent quantum jumps via quantum dot resonance fluorescence

Abstract

Reliable preparation, manipulation and measurement protocols are necessary to exploit a physical system as a quantum bit1. Spins in optically active quantum dots offer one potential realization2,3 and recent demonstrations have shown high-fidelity preparation4,5 and ultrafast coherent manipulation6,7,8. The final challenge—that is, single-shot measurement of the electron spin—has proved to be the most difficult of the three and so far only time-averaged optical measurements have been reported9,10,11,12. The main obstacle to optical spin readout in single quantum dots is that the same laser that probes the spin state also flips the spin being measured. Here, by using a gate-controlled quantum dot molecule13,14,15, we present the ability to measure the spin state of a single electron in real time via the intermittency of quantum dot resonance fluorescence12,16. The quantum dot molecule, unlike its single quantum dot counterpart, allows separate and independent optical transitions for state preparation, manipulation and measurement, avoiding the dilemma of relying on the same transition to address the spin state of an electron.

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Figure 1: Sample structure and quantum dot molecule transition diagram.
Figure 2: Steady-state two-colour resonance fluorescence.
Figure 3: Measurement of spin quantum jumps via intermittent resonance fluorescence.
Figure 4: Measurement fidelity.

References

  1. Nielsen, M. A. & Chuang, I. L. Quantum Computation and Quantum Information (Cambridge University Press, 2000)

    MATH  Google Scholar 

  2. Hanson, R. & Awschalom, D. D. Coherent manipulation of single spins in semiconductors. Nature 453, 1043–1049 (2008)

    ADS  CAS  Article  Google Scholar 

  3. Imamoglu, A. et al. Quantum information processing using quantum dot spins and cavity QED. Phys. Rev. Lett. 83, 4204–4207 (1999)

    ADS  CAS  Article  Google Scholar 

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

    ADS  Article  Google Scholar 

  5. Gerardot, B. D. et al. Optical pumping of a single hole spin in a quantum dot. Nature 451, 441–443 (2008)

    ADS  CAS  Article  Google Scholar 

  6. Wu, Y. et al. Selective optical control of electron spin coherence in singly charged GaAs-Al0. 3Ga0. 7As quantum dots. Phys. Rev. Lett. 96, 097402 (2007)

    ADS  Article  Google Scholar 

  7. Berezovsky, J., Mikkelson, M. H., Stoltz, N. G., Coldren, L. A. & Awschalom, D. D. Picosecond coherent optical manipulation of a single electron spin in a quantum dot. Science 320, 349–352 (2008)

    ADS  CAS  Article  Google Scholar 

  8. Press, D., Ladd, T. D., Zhang, B. & Yamamoto, Y. Complete quantum control of a single quantum dot spin using ultrafast optical pulses. Nature 456, 218–221 (2008)

    ADS  CAS  Article  Google Scholar 

  9. Kroutvar, M. et al. Optically programmable electron spin memory using semiconductor quantum dots. Nature 432, 81–84 (2004)

    ADS  CAS  Article  Google Scholar 

  10. Berezovsky, J. et al. Nondestructive optical measurements of a single electron spin in a quantum dot. Science 314, 1916–1920 (2006)

    ADS  CAS  Article  Google Scholar 

  11. Atatüre, M., Dreiser, J., Badolato, A. & Imamoglu, A. Observation of Faraday rotation from a single confined spin. Nature Phys. 3, 101–106 (2007)

    ADS  Article  Google Scholar 

  12. Vamivakas, A. N., Zhao, Y., Lu, C.-Y. & Atatüre, M. Spin-resolved quantum dot resonance fluorescence. Nature Phys. 5, 198–202 (2009)

    ADS  Article  Google Scholar 

  13. Krenner, H. J. et al. Direct observation of controlled coupling in an individual quantum dot molecule. Phys. Rev. Lett. 94, 057402 (2005)

    ADS  CAS  Article  Google Scholar 

  14. Ortner, G. et al. Control of vertically coupled InGaAs/GaAs quantum dots with electric fields. Phys. Rev. Lett. 94, 157401 (2005)

    ADS  CAS  Article  Google Scholar 

  15. Stinaff, E. A. et al. Optical signature of coupled quantum dots. Science 311, 636–639 (2006)

    ADS  CAS  Article  Google Scholar 

  16. Flagg, E. B. et al. Resonantly driven coherent oscillations in a solid-state quantum emitter. Nature Phys. 5, 203–207 (2009)

    ADS  CAS  Article  Google Scholar 

  17. Dehmelt, H. G. Proposed 1014 Dv < v laser fluorescence spectroscopy on Tl+ mono-ion oscillator II (spontaneous quantum jumps). Bull. Am. Phys. Soc. 20, 60 (1975)

    Google Scholar 

  18. Nagourney, W., Sandberg, J. & Dehmelt, H. Shelved optical electron amplifier: observation of quantum jumps. Phys. Rev. Lett. 56, 2797–2799 (1986)

    ADS  CAS  Article  Google Scholar 

  19. Sauter, T., Neuhauser, W., Blatt, R. & Toschek, P. E. Observation of quantum jumps. Phys. Rev. Lett. 57, 1696–1698 (1986)

    ADS  CAS  Article  Google Scholar 

  20. Bergquist, J. C., Hulet, R. G., Itano, W. M. & Wineland, D. J. Observation of quantum jumps in a single atom. Phys. Rev. Lett. 57, 1699–1702 (1986)

    ADS  CAS  Article  Google Scholar 

  21. Basch, Kummer, S. & Bruchle, C. Direct spectroscopic observation of quantum jumps of a single molecule. Nature 373, 132–134 (1995)

    ADS  Article  Google Scholar 

  22. Leibfried, D., Blatt, R., Monroe, C. & Wineland, D. Quantum dynamics of single trapped ions. Rev. Mod. Phys. 75, 281–324 (2003)

    ADS  CAS  Article  Google Scholar 

  23. Imamoglu, A. Quantum computation using quantum dot spins and microcavities. Fortschr. Phys. 48, 987–997 (2000)

    CAS  Article  Google Scholar 

  24. Pazy, E., Calarco, T. & Zoller, P. Spin state readout by quantum jump technique: for the purpose of quantum computing. IEEE Trans. NanoTechnol. 3, 10–16 (2004)

    ADS  Article  Google Scholar 

  25. Lu, C.-Y. et al. Direct measurement of spin dynamics in InAs/GaAs quantum dots using time-revolved resonance fluorescence. Phys. Rev. B 81, 035332 (2010)

    ADS  Article  Google Scholar 

  26. Yilmaz, S. T., Fallahi, P. & Imamoglu, A. Quantum-dot-spin single-photon interface. Phys. Rev. Lett. 105, 033601 (2010)

    ADS  CAS  Article  Google Scholar 

  27. Kim, D. et al. Optical spin initialization and non-destructive measurement in a quantum dot molecule. Phys. Rev. Lett. 101, 236804 (2008)

    ADS  Article  Google Scholar 

  28. Fält, S. et al. Strong electron-hole exchange in coherently coupled quantum dots. Phys. Rev. Lett. 100, 106401 (2008)

    ADS  Article  Google Scholar 

  29. Robledo, L. et al. Conditional dynamics of interacting quantum dots. Science 320, 772–775 (2008)

    ADS  CAS  Article  Google Scholar 

  30. Doty, M. F. et al. Hole-spin mixing in InAs quantum dot molecules. Phys. Rev. B 81, 035308 (2010)

    ADS  Article  Google Scholar 

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Acknowledgements

This work was supported by grants and funds from the University of Cambridge, EPSRC Science and Innovation Awards, the QIPIRC and EPSRC grant number EP/ G000883/1. Y.Z. is supported by the A. v. Humboldt Foundation and LGFG. We thank A. Imamoglu, X. Marie, T. Amand, D. Gammon and D. Steel for discussions.

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Contributions

A.N.V., C.-Y.L., C.M., Y.Z. and M.A. designed and performed the experiments, and conducted the analysis. S.F. and A.B. contributed to the growth and fabrication of the samples. All authors contributed to writing the paper.

Corresponding authors

Correspondence to A. N. Vamivakas or M. Atatüre.

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The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Information comprising Calculation and differential transmission spectroscopy of quantum dot molecule states and optical transitions, Measurement of the optically induced spin-flip rate for the T+3/2 transition, and a Discussion of fidelity calculation. Supplementary Figures 1-3 with legends and additional references are also included. (PDF 1805 kb)

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Vamivakas, A., Lu, CY., Matthiesen, C. et al. Observation of spin-dependent quantum jumps via quantum dot resonance fluorescence. Nature 467, 297–300 (2010). https://doi.org/10.1038/nature09359

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