Purification enables an unbounded query separation in sequential quantum channel discrimination

arXiv:2609.40218 · quant-ph · Submitted 2026-09-30 · Read on arXiv

quant-ph

Submitted: 2026-09-30

Updated: 2026-10-05

Terminology

• Trace — 21× in this paper · explained in 2 episodes
• Score Function — 10× in this paper · explained in 4 episodes
• Entanglement — 7× in this paper · explained in 3 episodes
• Hilbert Space — 6× in this paper · explained in 2 episodes
• Quantum Circuits — 5× in this paper · explained in 2 episodes
• Fidelity — 3× in this paper · explained in 2 episodes
• No-Go Theorem — 1× in this paper · explained in 2 episodes
• Query Complexity — 1× in this paper · explained in 2 episodes

Sources

• Physical Purification of Quantum States
• Purifying and Reversible Physical Processes
• No Universal Purification in Quantum Mechanics
• Probabilistic and approximate universal quantum purification machines
• Conjugate queries can help
• Random dilation superchannel
• Random Stinespring superchannel: converting channel queries into dilation isometry queries
• Local Test for Unitarily Invariant Properties of Bipartite Quantum States
• Quantum channel tomography and estimation by local test
• Asymptotic estimation theory for a finite dimensional pure state model
• Optimal full estimation of qubit mixed states
• Memory effects in quantum channel discrimination
• Process POVM: A mathematical framework for the description of process tomography experiments
• Strict hierarchy between parallel, sequential, and indefinite-causal-order strategies for channel discrimination
• Unitary channel discrimination beyond group structures: Advantages of sequential and indefinite-causal-order strategies
• Theoretical framework for quantum networks
• Quantum Circuits Architecture
• Optimal covariant quantum networks
• Indefinite Quantum Causality
• Random purification channel made simple

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