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View Full Version : the modern view of decoherence: A layperson's qestion


Galteeth
Oct26-09, 03:54 PM
While I understand that the a single quantum can indeed exist in a superposition, does the interaction of various quanta exist in superpositions as well? If so, is the idea of a limit on the number of these interactions before a definite state is reached what is referred to as decoherence, and if that is correct what is the number of interactions?

Demystifier
Oct27-09, 05:59 AM
First of all, reaching a definite state is NOT called decoherence.

Galteeth
Oct27-09, 03:17 PM
First of all, reaching a definite state is NOT called decoherence.

I have been confused by wikipedia.

Demystifier
Oct28-09, 05:46 AM
I have been confused by wikipedia.
A citation from http://en.wikipedia.org/wiki/Decoherence :
"Decoherence does not generate actual wave function collapse. It only provides an explanation for the appearance of wavefunction collapse. ... Moreover, our observation tells us that this mixture looks like a proper quantum ensemble in a measurement situation, as we observe that measurements lead to the "realization" of precicely one state in the "ensemble". But within the framework of the interpretation of quantum mechanics, decoherence cannot explain this crucial step from an apparent mixture to the existence and/or perception of single outcomes."

Galteeth
Oct28-09, 04:39 PM
A citation from http://en.wikipedia.org/wiki/Decoherence :
"Decoherence does not generate actual wave function collapse. It only provides an explanation for the appearance of wavefunction collapse. ... Moreover, our observation tells us that this mixture looks like a proper quantum ensemble in a measurement situation, as we observe that measurements lead to the "realization" of precicely one state in the "ensemble". But within the framework of the interpretation of quantum mechanics, decoherence cannot explain this crucial step from an apparent mixture to the existence and/or perception of single outcomes."

Yes, after going back and reading more carefully, i actually got that on my own.