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Physical Foundations of Landauer’s Principle

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Part of the book series: Lecture Notes in Computer Science ((LNPSE,volume 11106))

Abstract

We review the physical foundations of Landauer’s Principle, which relates the loss of information from a computational process to an increase in thermodynamic entropy. Despite the long history of the Principle, its fundamental rationale and proper interpretation remain frequently misunderstood. Contrary to some misinterpretations of the Principle, the mere transfer of entropy between computational and non-computational subsystems can occur in a thermodynamically reversible way without increasing total entropy. However, Landauer’s Principle is not about general entropy transfers; rather, it more specifically concerns the ejection of (all or part of) some correlated information from a controlled, digital form (e.g., a computed bit) to an uncontrolled, non-computational form, i.e., as part of a thermal environment. Any uncontrolled thermal system will, by definition, continually re-randomize the physical information in its thermal state, from our perspective as observers who cannot predict the exact dynamical evolution of the microstates of such environments. Thus, any correlations involving information that is ejected into and subsequently thermalized by the environment will be lost from our perspective, resulting directly in an irreversible increase in thermodynamic entropy. Avoiding the ejection and thermalization of correlated computational information motivates the reversible computing paradigm, although the requirements for computations to be thermodynamically reversible are less restrictive than frequently described, particularly in the case of stochastic computational operations. There are interesting possibilities for the design of computational processes that utilize stochastic, many-to-one computational operations while nevertheless avoiding net entropy increase that remain to be fully explored.

This work was supported by the Laboratory Directed Research and Development program at Sandia National Laboratories and by the Advanced Simulation and Computing program under the U.S. Department of Energy’s National Nuclear Security Administration (NNSA). Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for NNSA under contract DE-NA0003525. Approved for public release, SAND2018-7205 C. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government.

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Notes

  1. 1.

    Boltzmann’s constant \(k_\mathrm {B}\approx 1.38 \times 10^{-23}\ \mathrm {J}/\mathrm {K}\), in traditional units. This constant was actually introduced by Planck in [2]. We discuss this history further in Sect. 3.1.

  2. 2.

    The mathematical fact, not initially fully understood by Landauer, that reversible computational processes can indeed avoid information loss was rigorously demonstrated by Bennett [3], using methods anticipated by Lecerf [4].

  3. 3.

    In this equation, W counts the number of distinct microstates consistent with a given macroscopic description of a system.

  4. 4.

    Intuitively, the more different values \(v_i\) there are, the more unlikely or improbable each individual value would seem to be, proportionally—not knowing anything else about the situation.

  5. 5.

    The rule that probabilities must always sum to 1 can be derived by considering the implications, under our definitions, of breaking down all possible events (regardless of their probability) into a set of equally-likely micro-alternatives; only the probability distributions that sum to 1 turn out to be epistemologically self-consistent in that scenario, but we will not detail that argument here.

  6. 6.

    I gave a detailed example of this information capacity relation (Eq. 8) in [22].

  7. 7.

    Note that this information-theoretic concept of correlation differs from, and is more generally applicable than, a statistical correlation coefficient between scalar numeric variables. General discrete variables do not require any numerical interpretation.

  8. 8.

    Shannon’s formula (our Eq. 4) for H is usually credited to him, but Shannon himself credits Boltzmann, the true originator of this concept.

  9. 9.

    A Hilbert space is a (typically) many-dimensional vector space equipped with an inner product operator, defined over a field that is usually the complex numbers \(\mathbb {C}\).

  10. 10.

    I.e., if \(S(\, \varPhi (s)\, |\, C(s)\, ) = \hat{S}(\,\varPhi (s)\,|\,C(s)\,))\), or in other words, if \(K(\varPhi (s)) = K(C(s))\), so we have no more knowledge about the physical state than the computational state.

References

  1. Landauer, R.: Irreversibility and heat generation in the computing process. IBM J. Res. Dev. 5(3), 183–191 (1961). https://doi.org/10.1147/rd.53.0183

    Article  MathSciNet  MATH  Google Scholar 

  2. Planck, M.: Ueber das Gesetz der Energieverteilung im normalspectrum. Annalen der Physik 309(3), 553–563 (1901)

    Article  Google Scholar 

  3. Bennett, C.H.: Logical reversibility of computation. IBM J. Res. Dev. 17(6), 525–532 (1973). https://doi.org/10.1147/rd.176.0525

    Article  MathSciNet  MATH  Google Scholar 

  4. Lecerf, Y.: Machines de Turing réversibles–Récursive insolubilité en \(n \in \rm N\) de l’equation \(u=\theta ^{n}u\), où \(\theta \) est un \(\ll \) isomorphisme de codes \(\gg \). Comptes Rendus Hebdomadaires des Séances de L’académie des Sciences 257, 2597–2600 (1963)

    Google Scholar 

  5. Bérut, A., Arakelyan, A., Petrosyan, A., Ciliberto, S., Dillenschneider, R., Lutz, E.: Experimental verification of Landauer’s principle linking information and thermodynamics. Nature 483(7388), 187–190 (2012). https://doi.org/10.1038/nature10872

    Article  Google Scholar 

  6. Orlov, A.O., Lent, C.S., Thorpe, C.C., Boechler, G.P., Snider, G.L.: Experimental test of Landauer’s Principle at the sub-\(k_{{\rm BT}}\) level. Jpn. J. Appl. Phys. 51(6S), 06FE10 (2012). https://doi.org/10.1143/JJAP.51.06FE10

    Article  Google Scholar 

  7. Jun, Y., Gavrilov, M., Bechhoefer, J.: High-precision test of Landauer’s principle in a feedback trap. Phys. Rev. Lett. 113(19), 190601 (2014). https://doi.org/10.1103/PhysRevLett.113.190601

    Article  Google Scholar 

  8. Yan, L.L., et al.: Single-atom demonstration of the quantum Landauer principle. Phys. Rev. Lett. 120(21), 210601 (2018). https://doi.org/10.1103/PhysRevLett.120.210601

    Article  Google Scholar 

  9. Frank, M.P.: Approaching the physical limits of computing. In: Proceedings 35th International Symposium on Multiple-Valued Logic (ISMVL 2005), Calgary, Canada, May 2005, pp. 168–185. IEEE (2005). https://doi.org/10.1109/ISMVL.2005.9

  10. Frank, M.P., DeBenedictis, E.P.: A novel operational paradigm for thermodynamically reversible logic: adiabatic transformation of chaotic nonlinear dynamical circuits. In: IEEE International Conference on Rebooting Computing (ICRC), San Diego, CA, October 2016. IEEE (2016). https://doi.org/10.1109/ICRC.2016.7738679

  11. Frank, M.P.: Foundations of generalized reversible computing. In: Phillips, I., Rahaman, H. (eds.) RC 2017. LNCS, vol. 10301, pp. 19–34. Springer, Cham (2017). https://doi.org/10.1007/978-3-319-59936-6_2

    Chapter  Google Scholar 

  12. Frank, M.P.: Foundations of generalized reversible computing. Extended author’s preprint of [11], https://cfwebprod.sandia.gov/cfdocs/CompResearch/docs/grc-rc17-preprint2.pdf. Accessed 6 June 2018

  13. Frank, M.P.: Generalized reversible computing. ArXiv preprint arXiv:1806.10183 [cs.ET] (2018)

  14. Frank, M.P.: Chaotic logic. In: Presentation, 2016 IEEE International Conference on Rebooting Computing (ICRC), San Diego, CA, October 2016. https://cfwebprod.sandia.gov/cfdocs/CompResearch/docs/Frank_ICRC2016_ChaoticLo-gic_presUUR+notes.pdf. Accessed 6 June 2018

  15. Likharev, K.: Dynamics of some single flux quantum devices: I. Parametric quantron. IEEE Trans. Magn. 13(1), 242–244 (1977). https://doi.org/10.1109/TMAG.1977.1059351

    Article  Google Scholar 

  16. Fredkin, E., Toffoli, T.: Conservative logic. Int. J. Theor. Phys. 21(3–4), 219–253 (1982). https://doi.org/10.1007/BF01857727

    Article  MathSciNet  MATH  Google Scholar 

  17. Drexler, K.E.: Nanosystems: Molecular Machinery, Manufacturing, and Computation. Wiley, New York (1992)

    Google Scholar 

  18. Younis, S.G., Knight Jr., T.F.: Practical implementation of charge recovering asymptotically zero power CMOS. In: Borriello, G., Ebeling, C. (eds.) Research in Integrated Systems: Proceedings of the 1993 Symposium, Seattle, WA, February 1993, pp. 234–250. MIT Press (1993)

    Google Scholar 

  19. Frank, M.P.: Generalizations of the reversible computing paradigm. In: Presentation, Workshop on “Thermodynamics and Computation: Towards a New Synthesis,” Santa Fe Institute, August 2017. https://cfwebprod.sandia.gov/cfdocs/CompResearch/docs/SFI-talk-final2_ho2up.pdf. Accessed 6 June 2018

  20. Frank, M.P.: Generalized reversible computing and the unconventional computing landscape. In: Presentation, Computer Systems Colloquium, Department of EE, Stanford University, October 2017. https://cfwebprod.sandia.gov/cfdocs/CompResearch/docs/Stanford-CS-colloq_v2_ho2up.pdf (slides), https://www.youtube.com/watch?v=IQZ_bQbxSXk (video of presentation). Accessed 6 June 2018

  21. Frank, M.P.: The indefinite logarithm, logarithmic units, and the nature of entropy. ArXiv preprint arXiv:physics/0506128 (2005)

  22. Frank, M.P.: The physical limits of computing. Comput. Sci. Eng. 4(3), 16–26 (2002). https://doi.org/10.1109/5992.998637

    Article  Google Scholar 

  23. Clausius, R.: On the motive power of heat, and on the laws which can be deduced from it for the theory of heat. Poggendorff’s Annalen der Physick, LXXIX (1850)

    Google Scholar 

  24. Boltzmann, L.: Weitere Studien über das Wärmegleichgewicht unter Gasmolekülen. Sitzungsberichte Akademie der Wissenschaften 66, 275–370 (1872)

    MATH  Google Scholar 

  25. Von Neumann, J.: Thermodynamik quantenmechanischer Gesamtheiten [Thermodynamics of Quantum Mechanical Quantities]. Nachrichten von der Gesellschaft der Wissenschaften zu Göttingen, Mathematisch-Physikalische Klasse 102, 273–291 (1927)

    MATH  Google Scholar 

  26. Von Neumann, J.: Mathematische Grundlagen der Quantenmechanik. Julius Springer, Heidelberg (1932)

    MATH  Google Scholar 

  27. Von Neumann, J.: Mathematical Foundations of Quantum Mechanics. Princeton University Press, Princeton (1955)

    MATH  Google Scholar 

  28. Shannon, C.E.: A mathematical theory of communication. Bell Syst. Tech. J. 27, 379–424 and 623–657 (1948). https://doi.org/10.1145/584091.584093

  29. Shannon, C.E.: The Mathematical Theory of Communication. University of Illinois Press, Urbana (1949)

    MATH  Google Scholar 

  30. Shannon, C.E.: Communication in the presence of noise. Proc. IRE 37(1), 10–21 (1949)

    Article  MathSciNet  Google Scholar 

  31. Harada, Y., Goto, E., Miyamoto, N.: Quantum flux parametron. In: 1987 International Electron Devices Meeting, Washington, DC, 6–9 December 1987. IEEE (1987). https://doi.org/10.1109/IEDM.1987.191439

  32. Hosoya, M., et al.: Quantum flux parametron–A single quantum flux device for Josephson supercomputer. IEEE Trans. Appl. Supercond. 1(2), 77–89 (1991). https://doi.org/10.1109/77.84613

    Article  Google Scholar 

  33. De Haas, W.J., Wiersma, E.C., Kramers, H.A.: Experiments on adiabatic cooling of paramagnetic salts in magnetic fields. Physica 1(1–6), 1–13 (1934). https://doi.org/10.1016/S0031-8914(34)90002-1

    Article  Google Scholar 

  34. Kunzler, J.E., Walker, L.R., Galt, J.K.: Adiabatic demagnetization and specific heat in ferrimagnets. Phys. Rev. 119(5), 1609 (1960). https://doi.org/10.1103/PhysRev.119.1609

    Article  Google Scholar 

  35. Pecharsky, V.K., Gschneidner Jr., K.A.: Magnetocaloric effect and magnetic refrigeration. J. Magn. Magn. Mater. 200(1–3), 44–56 (1999). https://doi.org/10.1016/S0304-8853(99)00397-2

    Article  Google Scholar 

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Frank, M.P. (2018). Physical Foundations of Landauer’s Principle. In: Kari, J., Ulidowski, I. (eds) Reversible Computation. RC 2018. Lecture Notes in Computer Science(), vol 11106. Springer, Cham. https://doi.org/10.1007/978-3-319-99498-7_1

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