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Negative entropy in quantum information theory

Quantum Physics · Submitted 3 Oct 1996

abstract compiled · 2026-09-23 · no language-model review

The authors' main claim We find that, unlike in Shannon theory, conditional entropies can be negative when considering quantum entangled systems such as an Einstein-Podolsky-Rosen pair, which leads to a violation of well-known bounds of classical information theory.

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arXiv IDquant-ph/9610005 (version 1)
Pith IDFHLHXKEE, Pith's permanent record of this paper and its review
CitationChris Adami (California Institute of Technology), Nicolas J. Cerf. "Negative entropy in quantum information theory." arXiv:quant-ph/9610005 (1996). https://pith.science/paper/FHLHXKEE
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What the abstract itself states, as probabilities: claims first 0.06 · states limitation 0.11 · human participants 0.02 · controlled comparison 0.05 · randomized assignment 0.01 · states quantitative result 0.14 · compares with prior results 0.77 · mentions code or data availability 0.02.

The abstract, sentence by sentence

arXiv listing abstract v1. Results and the main claim are underlined; .

We present a quantum information theory that allows for the consistent description of quantum entanglement. It parallels classical (Shannon) information theory but is based entirely on density matrices, rather than probability distributions, for the description of quantum ensembles. We find that, unlike in Shannon theory, conditional entropies can be negative when considering quantum entangled systems such as an Einstein-Podolsky-Rosen pair, which leads to a violation of well-known bounds of classical information theory. Negative quantum entropy can be traced back to ``conditional'' density matrices which admit eigenvalues larger than unity. A straightforward definition of mutual quantum entropy, or ``mutual entanglement'', can also be constructed using a ``mutual'' density matrix. Such a unified information-theoretic description of classical correlation and quantum entanglement clarifies the link between them: the latter can be viewed as ``super-correlation'' which can induce classical correlation when considering a ternary or larger system.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#sentencerolethe authors' own workstates the main conclusionstrength
s0 We present a quantum information theory that allows for the consistent description of quantum entanglement. contribution 1.00 0.90 0.17 asserted 0.98
s1 It parallels classical (Shannon) information theory but is based entirely on density matrices, rather than probability distributions, for the description of quantum ensembles. method 0.56 0.40 0.07 asserted 1.00
s2 We find that, unlike in Shannon theory, conditional entropies can be negative when considering quantum entangled systems such as an Einstein-Podolsky-Rosen pair, which leads to a violation of well-known bounds of classical information theory. result 1.00 0.91 0.62 asserted 1.00
s3 Negative quantum entropy can be traced back to ``conditional'' density matrices which admit eigenvalues larger than unity. interpretation 0.82 0.77 0.16 asserted 0.99
s4 A straightforward definition of mutual quantum entropy, or ``mutual entanglement'', can also be constructed using a ``mutual'' density matrix. contribution 0.93 0.87 0.09 asserted 0.69
s5 Such a unified information-theoretic description of classical correlation and quantum entanglement clarifies the link between them: the latter can be viewed as ``super-correlation'' which can induce classical correlation when considering a ternary or larger system. interpretation 1.00 0.74 0.42 asserted 0.91

What kind of paper the classifier reports this is: theoretical result 0.93 · evidence from proof or derivation 0.91.

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  • T body sentences
  • C citations
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Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

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Original abstract

We present a quantum information theory that allows for the consistent description of quantum entanglement. It parallels classical (Shannon) information theory but is based entirely on density matrices, rather than probability distributions, for the description of quantum ensembles. We find that, unlike in Shannon theory, conditional entropies can be negative when considering quantum entangled systems such as an Einstein-Podolsky-Rosen pair, which leads to a violation of well-known bounds of classical information theory. Negative quantum entropy can be traced back to ``conditional'' density matrices which admit eigenvalues larger than unity. A straightforward definition of mutual quantum entropy, or ``mutual entanglement'', can also be constructed using a ``mutual'' density matrix. Such a unified information-theoretic description of classical correlation and quantum entanglement clarifies the link between them: the latter can be viewed as ``super-correlation'' which can induce classical correlation when considering a ternary or larger system.

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2 arXiv papers cite this in 3 sentences

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