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quantum-sutter.bsky.social
David Sutter
@quantum-sutter.bsky.social
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Quantum information theorist at IBM Research
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quantum-sutter.bsky.social
David Sutter @quantum-sutter.bsky.social · Feb 5
Uhlmann's theorem states that the fidelity of two (mixed) states can be expressed in terms of their purifications (where the fidelity simplifies). In arxiv.org/abs/2502.01749 we generalize Uhlmann's theorem to Rényi relative entropies.
Uhlmann's theorem for relative entropies
Uhlmann's theorem states that, for any two quantum states $ρ_{AB}$ and $σ_A$, there exists an extension $σ_{AB}$ of $σ_A$ such that the fidelity between $ρ_{AB}$ and $σ_{AB}$ equals the fidelity betwe...
arxiv.org
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