W. H. Zurek, "Environment-induced superselection rules," Phys. Rev. D, vol. 26, pp. 1862, 1982.  Home/Search   Document Not in Database   Summary   APS   Related Articles   Check

....states also equal to D. Since all systems are really quantum mechanical, we might ask how the classical system may be represented in the formalism of quantum mechanics. The answer, which is the form of classical quantum correspondence I use, lies at least partly in the notion of decoherence [4, 5, 6, 7]. This is the idea that physical systems which behave classically are those which interact with their environment in such a way that the environment effectively measures them in some preferred basis. This process need not be literally a measurement. For example, any unitary 14 interaction ....

W. H. Zurek, "Environment-induced superselection rules," Phys. Rev. D, vol. 26, pp. 1862, 1982.

....Renaissance in studying foundational issues in quantum mechanics has been matched by a similar theoretical Renaissance. A particularly broad program, sometimes known under the rubric of the decoherence program has been advanced by Zurek and other researchers, starting in the early 1980s [202, 203]. Reviews of this material may be found in [208, 206] The decoherence program is an attempt to give a detailed explanation for how classical behaviour arises from quantum reality. Much of this problem is now well understood, at least in outline, but some fundamental problems remain. How may the ....

W. H. Zurek. Environment-induced super-selection rules. Phys. Rev. D, 26(8):1862--1880, 1982.

.... ae describes a mixed rather than a pure state, the degree of mixing being measured by the entropy S : GammaTr ae log ae. The simplest decoherence models considered typically have a two dimensional H sys coupled to an environment whose Hilbert space is also two [1 3] or at most finite [2,4] dimensional, although more realistic (infinite dimensional) environments have been used to investigate the absence of chiral superpositions in molecules [3] for example. Now, the Dirac equation describes the unitary evolution of a spin 1 2 particle the Hilbert space factors as H = H ....

....Gaussian so that there is a weaker correlation between chirality and position than for m = 0, and thus lower entropy. Since the spin system is coupled to an infinite dimensional position Hilbert space environment, not a small finite dimensional Hilbert space with a short Poincar e recurrence time [2 4], one might have expected even this weaker chirality position correlation to continue to build and the entropy to increase asymptotically to 1 just as it does for m = 0. This expectation is contradicted, however, by the m = 2 curve in Figure 1. In this case the entropy reaches a (local) maximum ....

W. H. Zurek, "Environment-induced superselection rules", Phys. Rev. D 26 (1982) 1862--1880.

....two beams. An example of this was analyzed in Ref. 121] where the system causing the destruction of coherence was another two level system in one beam. As a reaction to this paper, Zurek [157] published the now famous paper introducing the concept of a pointer basis. This paper and its successor [158] have spawned the enormous literature on environmental decoherence which has appeared over the past ten years (see Ref. 159] for a popular review) The only point which I wish to take from this literature is that it is very easy for superpositions such as (1.13) to be destroyed for all practical ....

W.H. Zurek, "Environment-induced superselection rules" Phys. Rev. D 26, 1862 (1982).

....sufficient, and finally macroscopic. The ever decreasing possibility of interference between macroscopically distinct wave functions due to typically uncontrollable interactions with the environment is nowadays often referred to as decoherence (Griffiths [35] Omnes [36] Leggett [37] Zurek [38], JoosZeh [39] and has been regarded (Gell Mann Hartle [40] as a crucial ingredient for extracting a quasiclassical domain of familiar experience from the quantum formalism itself (see also [41] One of the best descriptions of the mechanism of decoherence, though not the word itself, can be ....

W. H. Zurek. Environment-induced superselection rules. Physical Review D, 26:1862-- 1880, 1982.

.... in Schrodinger s equation among the many degrees of freedom, the amount of y disjointness in the supports of Phi and Psi will typically tend to increase dramatically as time goes on, with, as in a chain reaction, more and more degrees of freedom participating in this disjointness (see [13,42,64,38]; see also [12] When the effects of this dissipation or decoherence are taken into account, one finds that a small amount of y disjointness will often tend quickly to become sufficient, indeed becoming much more sufficient as time goes on, and very often indeed becoming macroscopic. ....

W. H. Zurek, Environment-induced superselection rules, Physical Review D 26 (1982), 1862--1880.

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