Heisenberg's Introduction of the “Collapse of the Wavepacket” into Quantum Mechanics

  1. Dr. Dietrich Papenfuß3,
  2. Professor Dr. Dieter Lüst4 and
  3. Professor Dr. Wolfgang P. Schleich5
  1. Raymond Y. Chiao1 and
  2. Paul G. Kwiat2

Published Online: 29 NOV 2007

DOI: 10.1002/9783527610853.ch25

100 Years Werner Heisenberg: Works and Impact

100 Years Werner Heisenberg: Works and Impact

How to Cite

Chiao, R. Y. and Kwiat, P. G. (2002) Heisenberg's Introduction of the “Collapse of the Wavepacket” into Quantum Mechanics, in 100 Years Werner Heisenberg: Works and Impact (eds D. Papenfuß, D. Lüst and W. P. Schleich), Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany. doi: 10.1002/9783527610853.ch25

Editor Information

  1. 3

    Alexander von Humboldt-Stiftung, Bonn, Germany

  2. 4

    Humboldt Universität, Institut für Physik, Germany

  3. 5

    Universität Ulm, Abteilung f. Quantenphysik, Albert-Einstein-Allee 11, 89069 Ulm, Germany

Author Information

  1. 1

    Department of Physics, University of California, Berkeley, CA 94720-7300, USA

  2. 2

    Department of Physics, University of Illinois, Urbana, IL 61801, USA

Publication History

  1. Published Online: 29 NOV 2007
  2. Published Print: 27 AUG 2002

ISBN Information

Print ISBN: 9783527403929

Online ISBN: 9783527610853

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Keywords:

  • quantum physics;
  • Heisenberg's introduction of “collapse of the wavepacket”;
  • quantum mechanics;
  • quantum theory;
  • pair of daughter photons;
  • sum of their two energies was equal to the sharp energy of their parent photon;
  • wavepacket of one daughter photon collapsed;
  • total energy of the two-photon system was conserved

Summary

Heisenberg in 1929 introduced the “collapse of the wavepacket” into quantum theory. We review here an experiment at Berkeley, which demonstrated several aspects of this idea. In this experiment, a pair of daughter photons was produced in an entangled state, in which the sum of their two energies was equal to the sharp energy of their parent photon, in the nonlinear optical process of spontaneous parametric down-conversion. The wavepacket of one daughter photon collapsed upon a measurement-at-a-distance of the other daughter's energy, in such a way that the total energy of the two-photon system was conserved. Heisenberg's energy-time uncertainty principle was also demonstrated to hold in this experiment.