In the 1980s, theoretical estimates showed that on macroscopic scales decoherence occurs extremely rapidly, thus effectively precluding the observation of nonclassi-cal ► superposition states [21–23]. This immediately led to the question of how we may experimentally observe the continuous action of ► decoherence and thus the smooth transition from quantum to classical. Several challenges have to be overcome in the design of such experiments. The system is to be prepared in a non-classical superposition of mesoscopically or even macroscopically distinguishable states (► Schrodinger-cat state) with a sufficiently long decoherence time such that the gradual action of decoherence can be resolved. The existence of the superposition must be verified, and a scheme for monitoring decoherence must be devised that introduces a minimal amount of additional decoherence. Starting in the mid-1990s, several such experiments have been successfully performed, using physical systems such as:
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Cavity QED (atom-photon interactions) [1];
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Fullerenes (C60, C70) and other mesoscopic molecules [2];
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Superconducting systems (SQUIDs, Cooper-pair boxes) [3].
Other experimental domains are promising candidates for the observation of de-coherence; however, the necessary superposition states have not yet been realized:
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Bose-Einstein condensates [24];
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Nano-electromechanical systems [4].
Keywords
Josephson Junction Cooper Pair Superposition State Mechanical Resonator Decoherence Time
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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Primary Literature
- 1.J. M. Raimond, M. Brune, S. Haroche: Manipulating quantum entanglement with atoms and photons in a cavity. Rev. Mod. Phys. 73, 565–582 (2001).CrossRefADSMathSciNetGoogle Scholar
- 2.M. Arndt, K. Hornberger, A. Zeilinger: Probing the limits of the quantum world. Phys. World 18, 35–40 (2005).Google Scholar
- 3.A. J. Leggett: Testing the limits of quantum mechanics: motivation, state of play, prospects. J. Phys. Condens. Matter 14, R415–R451 (2002).CrossRefADSGoogle Scholar
- 4.M. Blencowe: Quantum electromechanical systems. Phys. Rep. 395, 159–222 (2004).CrossRefADSGoogle Scholar
- 5.J. F. Poyatos, J. I. Cirac, P. Zoller: Quantum reservoir engineering with laser cooled trapped ions. Phys. Rev. Lett. 77, 4728–4731 (1996).CrossRefADSGoogle Scholar
- 6.M. Tegmark: Apparent wave function collapse caused by scattering. Found. Phys. Lett. 6, 571–590 (1993).Google Scholar
- 7.A. Bassi, G. C. Ghirardi: Dynamical reduction models. Phys. Rep. 379, 257–426 (2003).MATHCrossRefADSMathSciNetGoogle Scholar
- 8.M. Brune, E. Hagley, J. Dreyer, X. Maître, A. Maali, C. Wunderlich, J. M. Raimond, S. Haroche: Observing the progressive decoherence of the “meter” in a quantum measurement. Phys. Rev. Lett. 77, 4887–4890 (1996).CrossRefADSGoogle Scholar
- 9.A. Auffeves, P. Maioli, T. Meunier, S. Gleyzes, G. Nogues, M. Brune, J. M. Raimond, S. Haroche: Entanglement of a mesoscopic field with an atom induced by photon graininess in a cavity. Phys. Rev. Lett. 91, 230405 (2003).CrossRefADSGoogle Scholar
- 10.K. Hornberger, Thermal limitation of far-field matter-wave interference. Phys. Rev. A 73, 052102 (2006).CrossRefADSGoogle Scholar
- 11.A. J. Leggett: Macroscopic quantum systems and the quantum theory of measurement. Suppl. Prog. Theor. Phys. 69, 80–100 (1980).CrossRefADSMathSciNetGoogle Scholar
- 12.J. R. Friedman, V. Patel, W. Chen, S. K. Yolpygo, J. E. Lukens: Quantum superposition of distinct macroscopic states. Nature 406, 43–46 (2000).CrossRefADSGoogle Scholar
- 13.C. H. van der Wal, A. C. J. ter Haar, F. K. Wilhelm, R. N. Schouten, C. J. P. M. Harmans, T. P. Orlando, S. Lloyd, J. E. Mooij: Quantum superposition of macroscopic persistent-current states. Science 290, 773–777 (2000).CrossRefADSGoogle Scholar
- 14.I. Chiorescu, Y. Nakamura, C. J. P. M. Harmans, J. E. Mooij: Coherent quantum dynamics of a superconducting flux qubit. Science 21, 1869–1871 (2003).CrossRefADSGoogle Scholar
- 15.P. Bertet, I. Chiorescu, G. Burkard, K. Semba, C. J. P. M. Harmans, D. P. DiVincenzo, J. E. Mooij: Dephasing of a superconducting qubit induced by photon noise. Phys. Rev. Lett. 95, 257002 (2005).CrossRefADSGoogle Scholar
- 16.Y. Nakamura, Y. A. Pashkin, J. S. Tsai: Coherent control of macroscopic quantum states in a single-Cooper-pair box. Nature 398, 786–788 (1999).CrossRefADSGoogle Scholar
- 17.D. Vion, A. Aassime, A. Cottet, P. Joyez, H. Pothier, C. Urbina, D. Esteve, M. H. Devoret: Manipulating the quantum state of an electrical circuit. Science 296, 886–889 (2002).CrossRefADSGoogle Scholar
- 18.D. A. R. Dalvit, J. Dziarmaga, W. H. Zurek: Decoherence in Bose—Einstein condensates: Towards bigger and better Schrödinger cats. Phys. Rev. A 62, 013607 (2000).CrossRefADSGoogle Scholar
- 19.A. D. Armour, M. P. Blencowe, K. C. Schwab: Entanglement and decoherence of a micro-mechanical resonator via coupling to a Cooper-pair box. Phys. Rev. Lett. 88, 148301 (2002).CrossRefADSGoogle Scholar
- 20.M.D. LaHaye, O. Buu, B. Camarota, K.C. Schwab: Approaching the quantum limit of a non-mechanical resonator. Science 304, 74–77 (2004)CrossRefADSGoogle Scholar
Secondary Literature
- 21.M. Schlosshauer: Decoherence and the Quantum-to-Classical Transition (Springer, Berlin 2007).Google Scholar
- 22.E. Joos, H. D. Zeh, C. Kiefer, D. Giulini, J. Kupsch, I.-O. Stamatescu: Decoherence and the Appearance of a Classical World in Quantum Theory (Springer, New York 2003).Google Scholar
- 23.W. H. Zurek: Decoherence, einselection, and the quantum origins of the classical. Rev. Mod. Phys. 75, 715–775 (2003).CrossRefADSMathSciNetGoogle Scholar
- 24.R. Kaiser, C. Westbrook, F. David (Eds.): Coherent Atomic Matter Waves, Les Houches Session LXXII, Les Houches Summer School Series (Springer, Berlin 2001).Google Scholar
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