Multi-scale Decoherence and the Quantum-to-Classical Transition

[asklepian]

TL;DR

Recent research suggests that decoherence, the process explaining the quantum-to-classical transition, varies across different scales. This multi-scale approach may better explain classical behavior, linking concepts like Quantum Darwinism, relational quantum mechanics, and information theory.

Key points from literature:
1. Scale-dependent decoherence: Studies indicate that decoherence processes can vary significantly across different scales [1].
2. Hierarchical quantum-to-classical transition: Classical behavior may emerge from cumulative decoherence effects across multiple scales [2].
3. Quantum Darwinism: This concept proposes that classical reality emerges from the selection and amplification of quantum states robust across multiple environmental interactions [3].
4. Relational quantum mechanics: Some researchers are exploring how quantum states and observables might be defined relationally between different subsystems [4].
5. Information-theoretic approaches: There's growing interest in understanding quantum mechanics and the emergence of spacetime using principles from information theory [5].
6. Open quantum systems: There's growing interest in whether all quantum systems should be considered fundamentally open, interacting with their environments at various scales [6].
7. Holographic principles in cosmology: Some theoretical work explores how concepts from holography might apply to cosmological horizons, potentially relating to quantum information across scales [7].
8. Entanglement networks in quantum gravity: Emerging research in quantum gravity considers how spacetime might emerge from networks of entangled quantum systems [8].

Questions for discussion:
1. How might a multi-scale perspective on decoherence affect our understanding of the measurement problem in quantum mechanics?
2. What experimental approaches could potentially test these ideas about scale-dependent decoherence?
3. How does this relate to current research in quantum gravity, particularly regarding the emergence of classical spacetime?
4. How might the concept of fundamentally open quantum systems, if valid, affect our understanding of decoherence and the emergence of classical reality?

References:
[1] Zurek, W.H. (2003). Decoherence, einselection, and the quantum origins of the classical. Reviews of Modern Physics, 75(3), 715-775. DOI: 10.1103/RevModPhys.75.715
[2] Joos, E., Zeh, H.D., Kiefer, C., Giulini, D.J., Kupsch, J., & Stamatescu, I.O. (2003). Decoherence and the appearance of a classical world in quantum theory. Springer, Berlin, Heidelberg. DOI: 10.1007/978-3-662-05328-7
[3] Zurek, W.H. (2009). Quantum Darwinism. Nature Physics, 5(3), 181-188. DOI: 10.1038/nphys1202
[4] Rovelli, C. (1996). Relational quantum mechanics. International Journal of Theoretical Physics, 35(8), 1637-1678. DOI: 10.1007/BF02302261
[5] Al-Khalili, J., & Chen, E.K. (2024). The Decoherent Arrow of Time and the Entanglement Past Hypothesis. arXiv:2405.03418v1 [quant-ph]
[6] Breuer, H.P., & Petruccione, F. (2002). The theory of open quantum systems. Oxford University Press. DOI: 10.1093/acprofso/9780199213900.001.0001
[7] Bousso, R. (2002). The holographic principle. Reviews of Modern Physics, 74(3), 825-874. DOI: 10.1103/RevModPhys.74.825
[8] Cotler, J., & Strominger, A. (2022). The Universe as a Quantum Encoder. arXiv:2201.11658v2 DOI: 10.48550/arXiv.2201.11658

 

[asklepian]

FYI: I can't figure out how to remove the emoji from the 6th reference

 

[Lord Jestocost]

TL;DR Summary: Recent research suggests that decoherence, the process explaining the quantum-to-classical transition, varies across different scales. This multi-scale approach may better explain classical behavior, linking concepts like Quantum Darwinism, relational quantum mechanics, and information theory.

Questions for discussion:
1. How might a multi-scale perspective on decoherence affect our understanding of the measurement problem in quantum mechanics?

Is there really a “measurement problem” in quantum mechanics?

For example: “There is no quantum measurement problem” by N. David Mermin (Physics Today 75, 6, 62 (2022))

 

[PeterDonis]

Is there really a “measurement problem” in quantum mechanics?

For example: “There is no quantum measurement problem” by N. David Mermin (Physics Today 75, 6, 62 (2022))

This is really an interpretation dependent question, and discussion of it would belong in a separate thread in the interpretations subforum.

Mermin thinks there isn't a measurement problem because his preferred interpretation is the MWI, in which that is in fact the case. But that does not mean he has solved the measurement problem, period. Not all interpretations agree with the MWI on this point.