Related papers: Strong Converse Exponent of Quantum State Merging

Strong Converse Exponent of Quantum State Merging

URL: http://arxiv.org/abs/2608.27202v1
Date: Thu, 27 Aug 2026 14:47:14 GMT
Title: Strong Converse Exponent of Quantum State Merging
Abstract summary: We determine the strong converse exponent for the entanglement cost of quantum state merging.<n>We derive the strong converse exponent of the partially smoothed conditional min-entropy in purified distance.
Score: 26.62118083599398
License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Abstract: We determine the strong converse exponent for the entanglement cost of quantum state merging, showing that it is characterized by the optimized $α$-$z$ conditional Rényi entropies with $z=α/2\in[1/2,1]$. This contrasts with the sandwiched conditional Rényi entropies that typically govern strong converse exponents in quantum information theory. As a consequence, we derive the strong converse exponent of the partially smoothed conditional min-entropy in purified distance. This exponent is governed by club-sandwiched conditional entropies, whereas global smoothing leads to a sandwiched expression.

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