Non-Markovian Effects in Spontaneous Emission: Deviations from the Exponential Decay ‘Law’

  • Peter L. Knight
Conference paper


In this paper we re-examine the validity of the exponential decay law in atomic spontaneous emission theory. The observation of exponential decay is considered by many to test quantum electrodynamics (QED) in a fundamental dynamical sense. We have to date no evidence which contradicts QED, but the increasing utilization of tunable coherent light sources has made possible optical tests in totally new regimes until very recently inaccessible to the experimentalist. It is now possible to investigate the detailed dynamical evolution of strongly excited atoms and to examine with some precision the associated spectrum of the radiated field. In such an investigation it is important to discriminate between a test of the basic principles of QED and a test of commonly used but subsidiary approximations made within QED.


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  1. 1.
    P. W. Milonni, Phys. Reports 25C, 1 (1976); T. Von Foerster, Amer. J. Phys. 40, 854 (1972).Google Scholar
  2. 2.
    L. A. Khalfin, Sov. Phys. JETP 6, 1053 (1958).ADSzbMATHGoogle Scholar
  3. 3.
    J. Mostowski and K. Wódiewicz, Bull. de l’Acad. Polonaise des Sciences 21, 1027 (1973).Google Scholar
  4. 4.
    P. L. Knight and P. W. Milonni, Phys. Lett. 56A,275 (1976) and references therein.Google Scholar
  5. 5.
    L. Fonda, Trieste preprint IC/76/20, and Proc. XIII Winter School of Theoretical Physics, February 1976, Karpacz, Poland.Google Scholar
  6. 6.
    A. Messiah, Quantum Mechanics, Vol. II (North-Holland, Amsterdam, 1961 ) pp. 994–1001.Google Scholar
  7. 7.
    G. Källen, in Encyclopaedia of Physics, Vol I, ed. S. Flügge (Springer, Berlin, 1958) pp. 274–279. W. H. Louisell, Quantum Statistical Properties of Radiation ( Wiley, New York, 1973 ) p. 285–296.Google Scholar
  8. 8.
    P. L. Knight, Phys. Lett. 61A, 25 (1977).Google Scholar
  9. 9.
    E. A. Power, Introductory Quantum Electrodynamics ( Longmans, London, 1964 ) pp. 113–116.zbMATHGoogle Scholar
  10. 10.
    J. H. Eberly and L. P. S. Singh, Phys. Rev. D7, 359 (1973).ADSGoogle Scholar
  11. 11.
    A. Messiah, Quantum Mechanics, Vol. I (North-Holland, Amsterdam, 1961 ) p. 320.Google Scholar
  12. 12.
    J. R. Ackerhalt, P. L. Knight and J. H. Eberly, Phys. Rev. Lett. 30, 456 (1973). J. R. Ackerhalt and J. H. Eberly, Phys. Rev. D10, 3350 (1974).Google Scholar
  13. 13.
    K. Wódkiewicz and J. H. Eberly, Ann. Phys. (N.Y.) 101, 574 (1976).ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1978

Authors and Affiliations

  • Peter L. Knight
    • 1
  1. 1.Royal Holloway CollegeUniversity of LondonEngland

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