Conditional Entropy and Information of Bipartite Quantum Processes
The authors develop an axiomatic approach to define the conditional entropy of bipartite quantum channels, which can reveal important features of the channel's causal structure that are not captured by the entropy of quantum channels or the conditional entropy of bipartite states.
Tight Characterization of Error Exponent for Classical-Quantum Channel Coding with Activated Non-Signaling Assistance
The optimal error exponent for classical-quantum channel coding assisted by activated non-signaling correlations is equal to the well-known sphere packing bound, which can be written as a single-letter formula optimized over Petz-Rényi divergences. This characterization remains tight for arbitrarily low rates below the channel capacity.
Generalized Quantum Stein's Lemma and Its Application to the Second Law of Quantum Resource Theories
The generalized quantum Stein's lemma characterizes the optimal performance of a variant of quantum hypothesis testing, which enables the formulation of a general framework for quantum resource theories with a second law analogous to that of thermodynamics.
Bounds on One-Shot Information Transmission Capacities of Discrete-Time Quantum Markov Semigroups
The authors derive upper and lower bounds on the one-shot ε-error information transmission capacities (classical, quantum, entanglement-assisted classical, and private classical) of a discrete-time quantum Markov semigroup in terms of the structure of the peripheral space of the underlying quantum channel.
Optimal Asymptotic Error Exponent for Quantum Entanglement Distillation
The optimal asymptotic error exponent for quantum entanglement distillation is given by the reverse relative entropy of entanglement, a single-letter quantity that can be evaluated using only a single copy of the quantum state.
Determining the Optimal Reliability Function for Transmitting Classical Information over Quantum Channels
The reliability function, which describes the optimal exponent of the decay of decoding error when the communication rate is below the capacity, has been determined for general classical-quantum channels.
Necessary and Sufficient Conditions for Saturating the Multiparameter Quantum Cramér-Rao Bound with Projective Measurements
The multiparameter quantum Cramér-Rao bound can be saturated at the single-copy level by a projective measurement if and only if the symmetric logarithmic derivatives of the quantum state commute and a unitary solution exists to a system of coupled nonlinear partial differential equations.
Efficiently Bounding Contraction and Expansion Coefficients for Quantum Channels Using Quantum Doeblin Coefficients
Quantum Doeblin coefficients provide an efficiently computable upper bound on a wide class of contraction coefficients, which quantify the decrease in information under quantum channels. The author also introduces reverse Doeblin coefficients that lower bound certain expansion coefficients.
양자 연성 덮개 보조정리와 율-왜곡 부호화, 해결성 및 양자 채널을 통한 식별에의 응용
양자 연성 덮개 보조정리를 이용하여 양자 채널 식별 문제에 대한 새로운 상한계를 제시하고, 동시 식별 용량과 무제한 식별 용량 사이의 분리를 증명하였다.
Quantum Soft-Covering Lemma and its Applications to Rate-Distortion Coding, Channel Resolvability, and Identification via Quantum Channels
The quantum soft-covering problem aims to find the minimum rank of an input state needed to approximate a given quantum channel output. The authors prove a one-shot quantum soft-covering lemma and demonstrate its applications in rate-distortion coding, channel resolvability, and identification capacities of quantum channels.
