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Entanglement in fermion systems

Quantum Physics · Submitted 20 Sep 2015

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

The authors' main claim For general pure states of such a system a closed expression for the fermionic concurrence is derived, which generalizes the Slater correlation measure defined in [J. Schliemann et al, Phys. Rev. A 64, 022303 (2001)], implying that "particle entanglement" may be seen as minimum "mode entanglement".

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arXiv ID1509.05970 (version 2)
Pith IDGGCZPPSI, Pith's permanent record of this paper and its review
CitationN. Gigena, R.Rossignoli. "Entanglement in fermion systems." arXiv:1509.05970 (2015). https://pith.science/paper/GGCZPPSI
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What the abstract itself states, as probabilities: claims first 0.10 · states limitation 0.24 · human participants 0.01 · controlled comparison 0.02 · randomized assignment 0.01 · states quantitative result 0.26 · compares with prior results 0.92 · mentions code or data availability 0.02.

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arXiv listing abstract v2. Results and the main claim are underlined; .

We analyze the problem of quantifying entanglement in pure and mixed states of fermionic systems with fixed number parity yet not necessarily fixed particle number. The "mode entanglement" between one single-particle level and its orthogonal complement is first considered, and an entanglement entropy for such a partition of a particular basis of the single-particle Hilbert space $\mathcal H$ is defined. The sum over all single-particle modes of this entropy is introduced as a measure of the total entanglement of the system with respect to the chosen basis and it is shown that its minimum over all bases of $\mathcal H$ is a function of the one-body density matrix. Furthermore, we show that if minimization is extended to all bases related through a Bogoliubov transformation, then the entanglement entropy is a function of the generalized one-body density matrix. These results are then used to quantify entanglement in fermion systems with four single-particle levels. For general pure states of such a system a closed expression for the fermionic concurrence is derived, which generalizes the Slater correlation measure defined in [J. Schliemann et al, Phys. Rev. A 64, 022303 (2001)], implying that "particle entanglement" may be seen as minimum "mode entanglement". It is also shown that the entanglement entropy defined before is related to this concurrence by an expression analogous to that of the two-qubit case. For mixed states of this system the convex roof extension of the previous concurrence and entanglement entropy are evaluated analytically, extending the results of previous ref. to general states.

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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 analyze the problem of quantifying entanglement in pure and mixed states of fermionic systems with fixed number parity yet not necessarily fixed particle number. contribution 0.67 0.85 0.07 asserted 0.71
s1 The "mode entanglement" between one single-particle level and its orthogonal complement is first considered, and an entanglement entropy for such a partition of a particular basis of the single-particle Hilbert space $\mathcal H$ is defined. contribution 0.60 0.91 0.05 asserted 0.99
s2 The sum over all single-particle modes of this entropy is introduced as a measure of the total entanglement of the system with respect to the chosen basis and it is shown that its minimum over all bases of $\mathcal H$ is a function of the one-body density matrix. result 0.60 0.94 0.19 asserted 1.00
s3 Furthermore, we show that if minimization is extended to all bases related through a Bogoliubov transformation, then the entanglement entropy is a function of the generalized one-body density matrix. result 0.96 0.95 0.12 asserted 1.00
s4 These results are then used to quantify entanglement in fermion systems with four single-particle levels. contribution 0.71 0.91 0.07 asserted 0.99
s5 For general pure states of such a system a closed expression for the fermionic concurrence is derived, which generalizes the Slater correlation measure defined in [J. Schliemann et al, Phys. Rev. A 64, 022303 (2001)], implying that "particle entanglement" may be seen as minimum "mode entanglement". result 0.88 0.94 0.37 hedged possibility 0.69
s6 It is also shown that the entanglement entropy defined before is related to this concurrence by an expression analogous to that of the two-qubit case. result 0.99 0.92 0.12 asserted 1.00
s7 For mixed states of this system the convex roof extension of the previous concurrence and entanglement entropy are evaluated analytically, extending the results of previous ref. to general states. result 0.52 0.93 0.12 asserted 1.00

What kind of paper the classifier reports this is: theoretical result 0.97 · evidence from proof or derivation 1.00.

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The paper
Original abstract

We analyze the problem of quantifying entanglement in pure and mixed states of fermionic systems with fixed number parity yet not necessarily fixed particle number. The "mode entanglement" between one single-particle level and its orthogonal complement is first considered, and an entanglement entropy for such a partition of a particular basis of the single-particle Hilbert space $\mathcal H$ is defined. The sum over all single-particle modes of this entropy is introduced as a measure of the total entanglement of the system with respect to the chosen basis and it is shown that its minimum over all bases of $\mathcal H$ is a function of the one-body density matrix. Furthermore, we show that if minimization is extended to all bases related through a Bogoliubov transformation, then the entanglement entropy is a function of the generalized one-body density matrix. These results are then used to quantify entanglement in fermion systems with four single-particle levels. For general pure states of such a system a closed expression for the fermionic concurrence is derived, which generalizes the Slater correlation measure defined in [J. Schliemann et al, Phys. Rev. A 64, 022303 (2001)], implying that "particle entanglement" may be seen as minimum "mode entanglement". It is also shown that the entanglement entropy defined before is related to this concurrence by an expression analogous to that of the two-qubit case. For mixed states of this system the convex roof extension of the previous concurrence and entanglement entropy are evaluated analytically, extending the results of previous ref. to general states.

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5 arXiv papers cite this in 7 sentences

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Uses its method or tool 1 paper
  • We also use the single-orbital entanglement entropy, $S_i = -(1-γ_i) log_2 (1-γ_i) -γ_i log_2 γ_i$, with $γ_i= ⟨ψ(θ) |a^†_i a_i |ψ(θ) ⟩$ , bound between $0$ and $1$, to evaluate the importance of quantum correlations in the ansatz [ref] .

    Nuclear shell-model simulation in digital quantum computers · Simulations · 0.87

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