On the role of entanglement in Schrödinger’s cat paradox

Stefan Rinner 1  and Ernst Werner 1
  • 1 Institut für Theoretische Physik, Universität Regensburg, Regensburg, Germany

Abstract

In this paper we re-investigate the core of Schrödinger’s “cat paradox”. We argue that one has to distinguish clearly between superpositions of macroscopic cat states |☺〉 + |☹〉 and superpositions of entangled states |☺, ↑〉 + |☹, ↓〉 which comprise both the state of the cat (☺=alive, ☹=dead) and the radioactive substance (↑=not decayed, ↓=decayed). It is shown, that in the case of the cat experiment recourse to decoherence or other mechanisms is not necessary in order to explain the absence of macroscopic superpositions. Additionally, we present modified versions of two quantum optical experiments as experimenta crucis. Applied rigorously, quantum mechanical formalism reduces the problem to a mere pseudo-paradox.

If the inline PDF is not rendering correctly, you can download the PDF file here.

  • [1] S. Gigan, et al., Nature 444, 67 (2006) http://dx.doi.org/10.1038/nature05273

  • [2] O. Arcizet, P.-F. Cohadon, T. Briant, M. Pinard, A. Heidmann, Nature 444, 71 (2006) http://dx.doi.org/10.1038/nature05244

  • [3] D. Kleckner, D. Bouwmeester, Nature 444, 75 (2006) http://dx.doi.org/10.1038/nature05231

  • [4] W. Marshall, C. Simon, R. Penrose, D. Bouwmeester, Phys. Rev. Lett. 91, 130401 (2003)

  • [5] O. Dannenberg, M. Mackie, Phys. Rev. A 74, 053601 (2006)

  • [6] A.J. Leggett, Science 307, 871 (2005) http://dx.doi.org/10.1126/science.1109541

  • [7] E. Schrödinger, Naturwissenschaften 23, 807; 823; 844 (1935) http://dx.doi.org/10.1007/BF01491891

  • [8] A. Einstein, B. Podolosky, N. Rosen, Phys. Rev. 47, 777 (1935) http://dx.doi.org/10.1103/PhysRev.47.777

  • [9] J. Dunningham, A. Rau, K. Burnett, Science 307, 872 (2005) http://dx.doi.org/10.1126/science.1109545

  • [10] R. Omnès, The Interpretation of Quantum Mechanics (Princeton University Press, Princeton, 1994)

  • [11] G. Auletta, Foundations and Interpretation of Quantum Mechanics (World Scientific Publishing Co. Pte. Ltd., Singapore, 2000)

  • [12] C. Monroe, et al., Science 272, 1131 (1996) http://dx.doi.org/10.1126/science.272.5265.1131

  • [13] M. Brune, et al., Phys. Rev. Lett. 77, 4887 (1996) http://dx.doi.org/10.1103/PhysRevLett.77.4887

  • [14] S. Schaufler, M. Freyberger, W. Schleich, J. Mod. Opt. 41, 1765 (1994) http://dx.doi.org/10.1080/09500349414551721

  • [15] L. Davidovich, M. Brune, J.M. Raimond, S. Haroche, Phys. Rev. A 53, 1295 (1996) http://dx.doi.org/10.1103/PhysRevA.53.1295

  • [16] S. Rinner, H. Walther, E. Werner, Phys. Rev. Lett. 93, 160407 (2004)

  • [17] S. Rinner, E. Werner, T. Becker, H. Walther, Phys. Rev. A 74, 041802(R) (2006)

  • [18] R. Penrose, The Large, the Small and the Human Mind (Cambridge University Press, Cambridge, 1997)

  • [19] J. von Neumann, Mathematische Grundlagen der Quantenmechanik (Springer Verlag, Berlin, 1932)

OPEN ACCESS

Journal + Issues

Open Physics (former Central European Journal of Physics) is a peer-reviewed Open Access journal, devoted to the publication of fundamental research results in all fields of physics.

Search