6 papers
Onset of superactivation of quantum capacity
Marco Parentin, Bjarne Bergh, Nilanjana Datta +1
Superactivation of quantum capacity is the phenomenon whereby two quantum channels, each with zero quantum capacity, can exhibit a strictly positive capacity when used in tandem. I…
Permutation Invariant Optimization Problems in Quantum Information Theory: A Framework for Channel Fidelity and Beyond
Bjarne Bergh, Marco Parentin
Exploiting permutation invariance to reduce the exponential scaling of semidefinite programs in quantum information has emerged as a powerful computational technique. In this work,…
Strong converse bounds on the classical identification capacity of the qubit depolarizing channel
Liuhang Ye, Bjarne Bergh, Nilanjana Datta
A strong converse bound for the classical identification capacity of a quantum channel is an upper bound on the asymptotic identification rate of classical messages sent through th…
Generalized Quantum Stein's Lemma and Reversibility of Quantum Resource Theories for Classical-Quantum Channels
Bjarne Bergh, Nilanjana Datta, Anirudh Khaitan
We extend the recent proof of the Generalized Quantum Stein's Lemma by Hayashi and Yamasaki [arXiv:2408.02722] to classical-quantum (c-q) channels. We analyze the composite hypothe…
Composite Classical and Quantum Channel Discrimination
Bjarne Bergh, Nilanjana Datta, Robert Salzmann
We study the problem of binary composite channel discrimination in the asymmetric setting, where the hypotheses are given by fairly arbitrary sets of channels, and samples do not h…
Continuity bounds for quantum entropies arising from a fundamental entropic inequality
Koenraad Audenaert, Bjarne Bergh, Nilanjana Datta +3
We establish a tight upper bound for the difference in von Neumann entropies between two quantum states, and . This bound is expressed in terms of the von Neumann entr…