Skip to main content
Log in

A Computational Model for Quantum Measurement

  • Published:
Quantum Information Processing Aims and scope Submit manuscript

Abstract

Is the dynamical evolution of physical systems objectively a manifestation of information processing by the universe? We find that an affirmative answer has important consequences for the measurement problem. In particular, we calculate the amount of quantum information processing involved in the evolution of physical systems, assuming a finite degree of fine-graining of Hilbert space. This assumption is shown to imply that there is a finite capacity to sustain the immense entanglement that measurement entails. When this capacity is overwhelmed, the system's unitary evolution becomes computationally unstable and the system suffers an information transition (“collapse”). Classical behavior arises from the rapid cycles of unitary evolution and information transition. Thus, the fine-graining of Hilbert space determines the location of the “Heisenberg cut”, the mesoscopic threshold separating the microscopic, quantum system from the macroscopic, classical environment. The model can be viewed as a probablistic complement to decoherence, that completes the measurement process by turning decohered improper mixtures of states into proper mixtures. It is shown to provide a natural resolution to the measurement problem and the basis problem.

PACS: 03.65.Ta; 03.67.-a; 03.67.Lx; 03.67.Mn

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

REFERENCES

  1. J. Krips, "Measurement in Quantum Theory", The Stanford Encyclopedia of Philosophy, Rob Clifton (ed.), URL = http://plato.stanford.edu/entries/qt-measurement/

  2. J. A. Wheeler and W. H. Zurek, Quantum Theory and Measurement (Princeton University Press, 1983).

  3. G. Ghirardi, Phys. Lett. A 262, 1(1999).

    Google Scholar 

  4. D. Home, Conceptual Foundations of Quantum Mechanics: An overview from Modern Perspectives (Plenum, New York, 1997).

    Google Scholar 

  5. M. A. Nielsen and I. Chuang, Quantum Computation and Quantum Information, (Cambridge, 2000).

  6. J. Preskill, Lecture Notes on Quantum Computation, http://www.theory.caltech.edu/people/preskill/p299/#lecture.

  7. J. von Neumann, The Mathematical Foundations of Quantum Mechanics, translated from German by R. T. Beyer (Princeton University Press, 1955).

  8. A. Bassi and G. Ghirardi, Phys. Lett. A 275, 373(2000).

    Google Scholar 

  9. E. Schrodinger, Naturwissenschaften 23, 807; 823; 844. (1935). English translation: John D. Trimmer, Proceedings of the American Philosophical Society, 124, 323-38 (1980), Reprinted in Quantum Theory and Measurement, pp. 152 (1983).

    Google Scholar 

  10. E. Joos and H. D. Zeh, Z. Phys. B59, 223(1985).

    Google Scholar 

  11. W. H. Zurek, Phys. Rev. D24, 1516, 1981; D26, 1862(1982)

    Google Scholar 

  12. W. H. Zurek, Phys. Today October (1991) p. 36.

  13. H. D. Zeh, in Proc. of Bielefeld conference on Decoherence: Theoretical, Experimental and Conceptual Problems, P. Blanchard, B. Giulini, R. Joos, C. Kiefer, I.-O. Stamatescu (eds.) (Springer, 1999); eprint quant-ph/9905004.

  14. A. Peres, Phys. Rev. A61 022116(2000).

    Google Scholar 

  15. D. A. Kokorowski, A. D. Kronin, T. D. Roberts and D. E. Pritchard, Phys. Rev. Lett. 86, 2191(2001).

    Google Scholar 

  16. S. L. Adler, eprint quant-ph/0112095.

  17. R. Joos, in Proc. of Bielefeld conference on Decoherence: Theoretical, Experimental and Conceptual Problems, P. Blanchard, B. Giulini, R. Joos, C. Kiefer, and I.-O. Stamatescu, eds. (Springer, 1999) pp. 1-17.

  18. B. d'Espagnat, in Preludes in Theoretical Physics, A. De-Shalit, A. Feshbach and L. van Hove, eds. (North Holland, 1966).

  19. A. Peres, Phys. Rev. A61, 022116.

  20. For example, a selective measurement in Ref. (31) apparently involves an abrupt 'jump' from an unrestricted set of worldlines in the Feynman propagator integral to narrower corridor of worldlines, consistent with the measurement read-out.

  21. H. Everett III, Rev. Mod. Phys. 29, 454(1957).

    Google Scholar 

  22. B. S. DeWitt, The Many-universes Interpretation of Quantum Mechanics in Foundations of Quantum Mechanics, (Academic Press, New York, 1971); reprinted in B. S. DeWitt and N. Graham, eds. p. 167 The Many-Worlds Interpretation of Quantum Mechanics, (Princeton University Press, 1973).

    Google Scholar 

  23. J. Barrett, "Everett's Relative-State Formulation of Quantum Mechanics," The Stanford Encyclopedia of Philosophy (Fall 2002 Edition), Edward N. Zalta (ed.), URL = http://plato.stanford.edu/archives/fall2002/entries/qm-everett/

  24. For example, if the initial state of S in Eq. (1) is \(\left( {1/\sqrt 2 |1} \right)\left( {\left( {1/\sqrt {23} |0 + \sqrt {22/23} } \right)} \right)\) in the measurement basis, it would suggest that a measurement in the \(\left\{ {|\left. 0 \right\rangle ,|\left. 1 \right\rangle } \right\}\) basis, in order to conform to the Born probability law, must cause the universe to branch out into 23 versions, exactly 1 of which goes into the |0〉 state. And if the coef.cients ai are irrational, then each measurement would seem to cause the universe to branch out into infinite versions.

  25. D. Albert and B. Loewer, Synthese 77, 195(1988).

    Google Scholar 

  26. R. B. Griffiths, J. Stat. Phys. 36, 219(1984).

    Google Scholar 

  27. R. Omnes, J. Stat. Phys. 53, 893(1988).

    Google Scholar 

  28. M. Gell-Mann and J. B. Hartle: in Complexity, Entropy, and the Physics of Information, Proc. of the Santa Fe Inst. Studies in the Sciences of Complexity vol. VIII, W. H. Zurek, ed. (Addison-Wesley, 1996).

  29. N. D. Mermin, Pramana 51, 549(1998); (eprint quant-ph/9609013); S. Saunders, Synthèse 102, 235(1995).

    Google Scholar 

  30. J. Barrett, Erkenntnis 41 233(1994); J. Barrett, The Quantum Mechanics of Minds and Worlds, (Oxford University Press, 1998); F. A. Dowker and A. Kent: eprint gr-qc/9412067.

    Google Scholar 

  31. M. Mensky, eprint quant-ph/0212112.

  32. M. Samal and P. Ghosh, eprint quant-ph/0202176.

  33. D. Bohm, The Undivided Universe (Routledge, 1993).

  34. G. Ghirardi, A. Rimini, and T. Weber, Phys. Rev. D 34 470(1986); G. C. Ghirardi, R. Grassi, F. Benatti, Found. of Phys., 25, 5(1995). G. C. Ghirardi, P. Pearle, A. Rimini Phys. Rev. A 42, 78(1990).

    Google Scholar 

  35. G. Ghirardi, "Collapse Theories," The Stanford Encyclopedia of Philosophy (Fall 2002 Edition), Edward N. Zalta (ed.), URL = http://plato.stanford.edu/archives/fall2002/entries/qm-collapse/

  36. R. Penrose, Gen. Rel. Grav. 28, 581(1996).

    Google Scholar 

  37. S. Lloyd, Nature 407, 1047(2000).

    Google Scholar 

  38. S. Lloyd, Phys. Rev. Lett. 88 (2002) 237901; eprint quant-ph/0110141.

    Google Scholar 

  39. C. Sivaram, Current Science 79, 413(2000).

    Google Scholar 

  40. Y. J. Ng, Phys. Rev. Lett. 86 2946(2001); Phys. Rev. Lett. 88 139902(2002).

    Google Scholar 

  41. A. K. Pati, S. R. Jain, A. Mitra, and R. Ramanna, Phys. Lett. A 301, 125(2002).

    Google Scholar 

  42. N. Margolus and L. B. Levitin, in PhysComp96, Proceedings of the Fourth Workshop on Physics and Computation, eds. T. Toffoli, M. Biafore, and J. Leao (New England Complex Systems Institute, Boston 1996); Physics (Amsterdam) 120D, 188(1998).

    Google Scholar 

  43. R. Landauer, Nature (London) 335, 779(1988).

    Google Scholar 

  44. J. D. Bekenstein, Phys. Rev. D23, 287(1981); Phys. Rev. Lett. 46, 623(1981); Phys. Rev. D30 1669(1984).

    Google Scholar 

  45. An Introduction to Kolmogorov Complexity and Its Applications, Ming Li and Paul Vitanyi, (Springer Verlag 1997).

  46. W. K. Wootters, Phys. Rev. D23, 357(1981)

    Google Scholar 

  47. S. L. Braunstein and C. M. Caves, Phys. Rev. Lett. 72, 3439(1994).

    Google Scholar 

  48. R. Schack, G. M. D'Ariano, and C. M. Caves, Phys. Rev. E 50, 972(1994).

    Google Scholar 

  49. J. von Neumann, Theory of Self-reproducing Automata Lect. 3 (Univ. of Illinois, Urbana, 1966).

    Google Scholar 

  50. W. K. Wooters and W. H. Zurek, Nature 299, 802(1982).

    Google Scholar 

  51. According to the holographic principle(40), the maximum information that can be registered in a system is A/l2 P; where A is the system's area. This would suggest \({\mathcal{M}} = \mu \left( {V/V_P } \right)^{{2 \mathord{\left/ {\vphantom {2 3}} \right. \kern-\nulldelimiterspace} 3}} \). This may be relevant in the quantum gravity regime, but for our purposes, we will quanitfy M as the volume Kolmogorov-Chaitin complexity.

  52. A. Einstein, B. Rosen, and B. Podolsky, Phys. Rev. 47, 777(1935).

    Google Scholar 

  53. P. Shor, SIAM J. Computing 26, 1484(1997).

    Google Scholar 

  54. R. P. Feynman, Int. J. Theor. Phys. 21, 467(1982).

    Google Scholar 

  55. T. Banks, W. Fischler, S. H. Shenker, and L. Susskind, Phys. Rev. D 55, 5112(1997).

    Google Scholar 

  56. Lee Smolin, Three Roads to Quantum Gravity (London: Weidenfeld and Nicholson, 2000); L. Crane, A. Perez, and C. Rovelli, Phys. Rev. Lett. 87, 181301(2001).

    Google Scholar 

  57. R. T. Cahill and C. M. Klinger, Phys. Lett. A223, 313(1996); Gen. Rel. & Grav. 32, 529(2000); R. T. Cahill, C. M. Klinger, and K. Kitto, The Physicist, 37, 191(2000).

    Google Scholar 

  58. A. Zeilinger, Found. of Phys. 29, 631(1999).

    Google Scholar 

  59. S. Wolfram, A New Kind of Science (Wolfram Media, 2002).

  60. H. Pagels, The Cosmic Code: Quantum Physics as the Language of Nature (Simon and Schuster, New York 1982).

    Google Scholar 

  61. A. Patel, J. Biosciences 27, 207(2002).

    Google Scholar 

  62. B. Georgeot and D. L. Shepelyansky, Phys. Rev. E62 3504(2000); B. Georgeot and D. L. Shepelyansky, Phys. Rev. E62, 6366(2000).

    Google Scholar 

  63. F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-correcting Codes (North-Holland 1977).

  64. Actually, the required clock rate should be ωχ \(\left( {{\mathcal{D}}'{\mathcal{P}}/{\mathcal{M}}} \right)\) where x = ((1/r)-1) and \({\mathcal{P}}\) is the number of elements in the parity check matrix,(63) given by \({\mathcal{P}}\) = μ2n2/r. For our estimate we ignore \({\mathcal{P}}\) which is polynomial in n: Also note that we are invoking a simple classical error correction procedure, rather than quantum error correction,(68) as the correction is supposed to be implemented on the state information rather than on quantum states.

  65. Segmentation fault occurs when there is invalid pointer de-referencing. In our case, the pointer is invalid because it is trying to access a piece of unallocated (or de-allocated) memory. In conventional computing, it can be invalid also because it is a NULL-pointer or an un-initialized pointer.

  66. A computer program is said to crash when it suffers a sudden major failure usually with attendant loss of data (Merriam-Webster dictionary; http://www.m-w.com).

  67. The core is the file that contains a snapshot of the memory registers at the time when a program crashes. It is 'dumped' into a compiler-specified directory when a program crashes.

  68. Calderbank and P. Shor, Phys. Rev. A 54, 1098(1996); A. Steane, Proc. Roy. Soc., London, Ser. A 452, 2551(1996).

    Google Scholar 

  69. M. Arndt, O. Nairz, J. Vos Andrae, C. Keller, G. van der Zouw and A. Zeilinger, Nature 401, 680(1999).

    Google Scholar 

  70. E. Altewischer, M. P. van Exter, and J. P. Woerdman, Nature 418, 304(2002).

    Google Scholar 

  71. The completeness of the measurement operators Ei is sufficient to prove this, ie., \(\sum\nolimits_i {E_i = I} \). If such completeness is not guaranteed, nonlocal signaling would be possible (G. C. Ghirardi, A. Rimini, and T. Weber, Lett. Nuovo Cimento 27, 293 (1980); R. Srikanth, Pramana 59, 169 (2002); errata in ibid. 59, 1076 (2002)). However, this still does not affect the 'derivation' of the Born rule for projective measurements in the computational model.

  72. S. Mayburov, eprint quant-ph/0212099.

  73. D. Bruss, eprint quant-ph/0110078.

  74. C. J. Myatt, B. E. King, Q. A. Turchette, C. Sackett, D. Kielpinski, W. Itano, C. Monroe, and D. J. Wineland, Nature 403, 269(2000).

    Google Scholar 

  75. A. Patel, J. Genetics 80 39(2001).

    Google Scholar 

  76. In fact, computational stability is only necessary but not sufficient to manifest coherent wavelike behaviour. In practice, it will also be necessary to take into consideration various energy or wavelength scales of the system (rotational, vibrational, etc.). The presence of such multiple internal degrees of freedom of comparable energy can lead to broad-band wavelength scales that can potentially wash out interference patterns.

  77. W. Marshall, Christoph Simon, R. Penrose, and D. Bouwmeester, eprint quant-ph/0210001.

  78. S. Yu. Kun, L. Benet, L. T. Chadderton, W. Greiner, and F. Haas, Phys. Rev. C, 67, 011604R (2003).

  79. E. F. Wigner, Rev. Mod. Phys. 25, 255(1957).

    Google Scholar 

  80. V. Scarani, W. Tittel, H. Zbinden, and N. Gisin, Phys. Lett. A 276 1(2000).

    Google Scholar 

  81. J. S. Bell, Physics 1, 195(1964).

    Google Scholar 

  82. R. Garisto, eprint quant-ph/0212078.

  83. H. Zbinden, J. Brendel, N. Gisin and W. Tittel, Phys. Rev. A 63, 022111-1 (2001).

    Google Scholar 

  84. J. Rembielinski and K. A. Smolinski, Phys. Rev. A 66, 052114(2002).

    Google Scholar 

  85. G. Lindblad, Commun. Math. Phys. 48, 119(1976).

    Google Scholar 

  86. V. Gorini, A. Kossakowski, and E. C. G. Sudarshan, J. Math. Phys. 17, 821(1976).

    Google Scholar 

  87. J. Anglin and W. Ketterle, Nature 416 211(2002).

    Google Scholar 

  88. J. R. Friedman, V. Patel, W. Chen, S. K. Tolpygo, and J. E. Lukens, Nature 406, 43(2000).

    Google Scholar 

  89. M. Mehrafarin, Found. Phys. Lett. 16(2003) 127 (eprint quant-ph/0205028).

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Srikanth, R. A Computational Model for Quantum Measurement. Quantum Information Processing 2, 153–199 (2003). https://doi.org/10.1023/B:QINP.0000004123.82268.f4

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1023/B:QINP.0000004123.82268.f4

Navigation