Affiliation:
1. Nagoya University
2. Okinawa Institute of Science and Technology Graduate University
3. Department of Applied Mathematics and Theoretical Physics, University of Cambridge
Abstract
Estimating the information transmission capability of a quantum channel remains one of the fundamental problems in quantum information processing. In contrast to classical channels, the information-carrying capability of quantum channels is contextual. One of the most significant manifestations of this is the superadditivity of the channel capacity: the capacity of two quantum channels used together can be larger than the sum of the individual capacities. Here, we present a one-parameter family of channels for which, as the parameter increases, its one-way quantum and private capacities increase while its two-way capacities decrease. We also exhibit a one-parameter family of states with analogous behavior with respect to the one- and two-way distillable entanglement and secret key. Our constructions demonstrate that noise is context dependent in quantum communication.
Published by the American Physical Society
2024
Funder
Ministry of Education, Culture, Sports, Science and Technology
Publisher
American Physical Society (APS)