dorsal/arxiv
View SchemaInformation and Entropy in Quantum Theory
| Authors | O. J. E. Maroney |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0411172 |
| URL | https://arxiv.org/abs/quant-ph/0411172 |
Abstract
We look at certain thought experiments based upon the 'delayed choice' and 'quantum eraser' interference experiments, which present a complementarity between information gathered from a quantum measurement and interference effects. It has been argued that these experiments show the Bohm interpretation of quantum theory is untenable. We demonstrate that these experiments depend critically upon the assumption that a quantum optics device can operate as a measuring device, and show that, in the context of these experiments, it cannot be consistently understood in this way. By contrast, we then show how the notion of 'active information' in the Bohm interpretation provides a coherent explanation of the phenomena shown in these experiments. We then examine the relationship between information and entropy. The thought experiment connecting these two quantities is the Szilard Engine version of Maxwell's Demon, and it has been suggested that quantum measurement plays a key role in this. We provide the first complete description of the operation of the Szilard Engine as a quantum system. This enables us to demonstrate that the role of quantum measurement suggested is incorrect, and further, that the use of information theory to resolve Szilard's paradox is both unnecessary and insufficient. Finally we show that, if the concept of 'active information' is extended to cover thermal density matrices, then many of the conceptual problems raised by this paradox appear to be resolved.
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"abstract": "We look at certain thought experiments based upon the \u0027delayed choice\u0027 and\n\u0027quantum eraser\u0027 interference experiments, which present a complementarity\nbetween information gathered from a quantum measurement and interference\neffects. It has been argued that these experiments show the Bohm interpretation\nof quantum theory is untenable. We demonstrate that these experiments depend\ncritically upon the assumption that a quantum optics device can operate as a\nmeasuring device, and show that, in the context of these experiments, it cannot\nbe consistently understood in this way. By contrast, we then show how the\nnotion of \u0027active information\u0027 in the Bohm interpretation provides a coherent\nexplanation of the phenomena shown in these experiments.\n We then examine the relationship between information and entropy. The thought\nexperiment connecting these two quantities is the Szilard Engine version of\nMaxwell\u0027s Demon, and it has been suggested that quantum measurement plays a key\nrole in this. We provide the first complete description of the operation of the\nSzilard Engine as a quantum system. This enables us to demonstrate that the\nrole of quantum measurement suggested is incorrect, and further, that the use\nof information theory to resolve Szilard\u0027s paradox is both unnecessary and\ninsufficient. Finally we show that, if the concept of \u0027active information\u0027 is\nextended to cover thermal density matrices, then many of the conceptual\nproblems raised by this paradox appear to be resolved.",
"arxiv_id": "quant-ph/0411172",
"authors": [
"O. J. E. Maroney"
],
"categories": [
"quant-ph"
],
"title": "Information and Entropy in Quantum Theory",
"url": "https://arxiv.org/abs/quant-ph/0411172"
},
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