Observation of Hanbury Brown–Twiss anticorrelations for free electrons

Abstract

Fluctuations in the counting rate of photons originating from uncorrelated point sources become, within the coherently illuminated area, slightly enhanced compared to a random sequence of classical particles. This phenomenon, known in astronomy as the Hanbury Brown–Twiss effect1,2,3,4,5, is a consequence of quantum interference between two indistinguishable photons and Bose–Einstein statistics6. The latter require that the composite bosonic wavefunction is a symmetric superposition of the two possible paths. For fermions, the corresponding two-particle wavefunction is antisymmetric: this excludes overlapping wave trains, which are forbidden by the Pauli exclusion principle. Here we use an electron field emitter to coherently illuminate two detectors, and find anticorrelations in the arrival times of the free electrons. The particle beam has low degeneracy (about 10-4 electrons per cell in phase space); as such, our experiment represents the fermionic twin of the Hanbury Brown–Twiss effect for photons.

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Figure 1: Electron optical set-up (top) and fast coincidence electronics (bottom) to measure electron anticorrelations.
Figure 2: Schematic time spectra expected for poissonian processes at infinite time resolution (straight lines) and an antibunched beam at finite resolving time in semilogarithmic representation.
Figure 3: Antibunching as a function of coherence of illumination of the collectors.

References

  1. 1

    Hanbury Brown, R. & Twiss, R. Q. A new type of interferometer for use in radio astronomy. Phil. Mag. 45, 663–682 (1954)

    ADS  Article  Google Scholar 

  2. 2

    Hanbury Brown, R. & Twiss, R. Q. Correlation between photons in two coherent beams of light. Nature 177, 27–29 (1956)

    ADS  Article  Google Scholar 

  3. 3

    Hanbury Brown, R. & Twiss, R. Q. The question of correlation between photons in coherent light rays. Nature 178, 1447–1448 (1956)

    ADS  Article  Google Scholar 

  4. 4

    Hanbury Brown, R. & Twiss, R. Q. Interferometry of the intensity fluctuation in light I. Proc. R. Soc. Lond. 242, 300–324 (1957)

    ADS  Article  Google Scholar 

  5. 5

    Hanbury Brown, R. & Twiss, R. Q. Interferometry of the intensity fluctuation in light II. An experimental test of the theory for partially coherent light. Proc. R. Soc. Lond. 243, 291–319 (1958)

    ADS  Article  Google Scholar 

  6. 6

    Purcell, E. M. The question of correlation between photons in coherent light rays. Nature 178, 1449–1450 (1956)

    ADS  CAS  Article  Google Scholar 

  7. 7

    Brannen, E. & Ferguson, H. I. S. The question of correlation between photons in coherent light beams. Nature 178, 481–482 (1956)

    ADS  CAS  Article  Google Scholar 

  8. 8

    Hanbury Brown, R. The Intensity Interferometer 7 (Taylor and Francis, New York, 1974)

    Google Scholar 

  9. 9

    Hanbury Brown, R. & Twiss, R. Q. A test of a new type of stellar interferometer on Sirius. Nature 178, 1046–1448 (1956)

    ADS  Article  Google Scholar 

  10. 10

    Silverman, M. P. On the feasibility of observing electron antibunching in a field-emission beam. Phys. Lett. A 120, 442–446 (1987)

    ADS  CAS  Article  Google Scholar 

  11. 11

    Kodama, T. et al. Feasibility of observing two-electron interference. Phys. Rev. A 57, 2781–2785 (1998)

    ADS  CAS  Article  Google Scholar 

  12. 12

    Henny, M. et al. The fermionic Hanbury Brown and Twiss experiment. Science 284, 296–298 (1999)

    ADS  CAS  Article  Google Scholar 

  13. 13

    Oliver, W. D., Kim, J., Liu, R. C. & Yamamoto, Y. Hanbury Brown and Twiss-type experiment with electrons. Science 284, 299–301 (1999)

    ADS  CAS  Article  Google Scholar 

  14. 14

    Twiss, R. Q. & Little, A. G. The detection of time-correlated photons by a coincidence counter. Aust. J. Phys. 12, 77–93 (1959)

    ADS  Article  Google Scholar 

  15. 15

    Hasselbach, F. A ruggedized miniature UHV electron biprism interferometer for new fundamental experiments and applications. Z. Phys. B 71, 443–449 (1988)

    ADS  Article  Google Scholar 

  16. 16

    Goldberger, M. L., Lewis, H. W. & Watson, K. M. Use of intensity correlations to determine the phase of a scattering amplitude. Phys. Rev. 132, 2764–2787 (1963)

    ADS  Article  Google Scholar 

  17. 17

    Silverman, M. P. New quantum effects of confined magnetic flux on electrons. Phys. Lett. A 118, 155–158 (1986)

    ADS  CAS  Article  Google Scholar 

  18. 18

    Silverman, M. P. in OSA Proceedings on Photon Correlation Techniques and Applications (eds Abbiss, J. B. & Smart, E. A.) Vol. 1 26–34 (OSA, Washington DC, 1988)

    Google Scholar 

  19. 19

    Silverman, M. P. Distinctive quantum features of electron intensity correlation interferometry. Il Nuovo Cimento 97, 200–219 (1987)

    Article  Google Scholar 

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Acknowledgements

We thank M. Silverman, M. Lenc, T. Tyc, A. Oed and P. Sonnentag for discussions, and the Deutsche Forschungsgemeinschaft for financial support.

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Correspondence to Franz Hasselbach.

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Kiesel, H., Renz, A. & Hasselbach, F. Observation of Hanbury Brown–Twiss anticorrelations for free electrons. Nature 418, 392–394 (2002). https://doi.org/10.1038/nature00911

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