The Role of Detector in Which-Way Experiment


Following Scully et al.’s study on the mechanism of complementarity, we further investigate the role of detector in which-way experiment. We will show that the initial quantum pure state of particle will reduce to a mixture state because of the inevitable interaction between particle and detector, then the coherence of wavefunction for the particle falling on the screen will be destroyed, which leads to the disappearance of interference fringes in which-way experiment.

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Z. Wang, "The Role of Detector in Which-Way Experiment," Journal of Quantum Information Science, Vol. 3 No. 1, 2013, pp. 20-22. doi: 10.4236/jqis.2013.31005.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] N. Bohr, “Das Quantenpostulat und die neuere Entwicklung der Atomistik,” Naturwissenschaften, Vol. 16, No. 15, 1928, pp. 245-257. doi:10.1007/BF01504968
[2] R. Feynman, R. Leighton and M. Sands, “The Feynman Lectures on Physics,” Addison Wesley, Reading, 1965.
[3] W. Heisenberg, “The Physical Principle of the Quantum Theory,” University of Chicago Press, Chicago, 1930.
[4] M. O. Scully, B. G. Englert and H. Walther, “Quantum Optical Tests of Complementarity,” Nature, Vol. 351, 1991, pp. 111-116. doi:10.1038/351111a0
[5] E. P. Storey, S. M. Tan, M. J. Collett and D. F. Walls, “Path Detection and the Uncertainty Principle,” Nature, Vol. 367, 1994, pp. 626-628. doi:10.1038/367626a0
[6] S. Durr, T. Nonn and G. Rempe, “Origin of Quantum Mechanical Complementary Probed by a ‘Which-Way’ Experiment in an Atom Interferometer,” Nature, Vol. 395, 1998, p. 33. doi:10.1038/25653
[7] M. S. Chapman, T. D. Hammond, A. Lenel, J. Schmiedmeyer, R. A. Rubinstein, E. Smith and D. E. Pritchard, “Photon Scattering from Atoms in an Atom Interferometer: Coherence Lost and Regained,” Physical Review Letters, Vol. 75, No. 21, 1995, pp. 3783-3787. doi:10.1103/PhysRevLett.75.3783
[8] E. Buks, R. Schuster, M. Heiblum, D. Mahalu and V. Umansky, “Dephasing in Electron Interference by a ‘Which-Path’ Detector,” Nature, Vol. 391, 1998, p. 871. doi:10.1038/36057
[9] W. H. Zurek, “Environment-Induced Superselection Rules,” Physical Review D, Vol. 26, No. 8, 1982, pp. 1862-1880. doi:10.1103/PhysRevD.26.1862

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