9 papers · 1 filter
Minimax games for quantum channel discrimination
Kun Fang, Michael X. Cao, Hao-Chung Cheng +2
Quantum channel discrimination is a primitive task for identifying, verifying, and benchmarking quantum dynamics. Previous studies have primarily considered either the best-case te…
No information transmission through quantum channels above capacity
Hao-Chung Cheng, Marco Tomamichel
We show that the capacity of a quantum channel demarcates a phase transition: while reliable transmission below capacity is always possible, any attempt to transmit information abo…
Strong Converse Exponent of Quantum State Merging
Mario Berta, Hao-Chung Cheng, Roberto Rubboli +1
We determine the strong converse exponent for the entanglement cost of quantum state merging, showing that it is characterized by the optimized - conditional Rényi entropies…
Sharp Continuity of Petz and Sandwiched Rényi Conditional Entropies
Hao-Chung Cheng, Po-Chieh Liu
We determine the sharp modulus of continuity, in trace distance, of the optimized Petz and sandwiched Rényi conditional entropies for every order . If two bipartit…
Superadditivity for Entanglement-Assisted Communication
Hao-Chung Cheng, Mario Berta
The entanglement-assisted capacity of a quantum channel admits an additive single-letter characterization, implying that joint encodings across channel uses cannot increase the ult…
Device-independent Quantum Key Distribution in the commuting operator framework
Gereon Koßmann, René Schwonnek, Po-Chieh Liu +1
Device-independent quantum key distribution (DIQKD) is arguably the gold standard for secure quantum communication, as it aims to rely only on observed input-output statistics of a…