Reliability Function of Classical-Quantum Channels.

Phys Rev Lett

Southern University of Science and Technology, Shenzhen Institute for Quantum Science and Engineering, Shenzhen 518055, China.

Published: January 2025

We study the reliability function of general classical-quantum channels, which describes the optimal exponent of the decay of decoding error when the communication rate is below the capacity. As the main result, we prove a lower bound, in terms of the quantum Rényi information in Petz's form, for the reliability function. This resolves Holevo's conjecture proposed in 2000, a long-standing open problem in quantum information theory. It turns out that the obtained lower bound matches the upper bound derived by Dalai in 2013, when the communication rate is above a critical value. Thus, we have determined the reliability function in this high-rate case. Our approach relies on Renes' breakthrough made in 2022, which relates classical-quantum channel coding to that of privacy amplification, as well as our new characterization of the channel Rényi information.

Download full-text PDF

Source
http://dx.doi.org/10.1103/PhysRevLett.134.010802DOI Listing

Publication Analysis

Top Keywords

reliability function
16
classical-quantum channels
8
communication rate
8
lower bound
8
reliability
4
function classical-quantum
4
channels study
4
study reliability
4
function general
4
general classical-quantum
4

Similar Publications

Antibodies in human milk protect infants against infections, but currently no assay is described that is able to simultaneously measure all 9 antibody isotypes and subclasses immunoglobulins in human fluids, such as human milk. Our cohort "Protecting against Respiratory tract Infections through human Milk Analysis" (PRIMA) is focused on the relation between the occurrence of respiratory infections during the first year of life and concentration of maternal antibodies in breastfeeding. We developed and successfully validated a multiplex assay that is able to measure all nine antibody isotypes and subclasses in human plasma and milk (regardeless of the pathogen specificity), using a small sample volume.

View Article and Find Full Text PDF

Brain age gap (BAG), the deviation between estimated brain age and chronological age, is a promising marker of brain health. However, the genetic architecture and reliable targets for brain aging remains poorly understood. In this study, we estimate magnetic resonance imaging (MRI)-based brain age using deep learning models trained on the UK Biobank and validated with three external datasets.

View Article and Find Full Text PDF

Central emotion theories assume that during threatening and dangerous events the human face signals a prototypical, distinct, and universally recognized expression of fear which can be accurately decoded by conspecific perceivers. Due to the importance of fear expressions, an unusually large body of research has been dedicated to exploring their evolutionary origins, neurobiological mechanisms, and clinical significance. However, these studies typically utilize highly recognizable posed actor portrayals presumed to closely resemble the diagnostic physical appearance of real-life fearful faces.

View Article and Find Full Text PDF

Background: The cerebellum is one of the major central nervous structures consistently altered in obesity. Its role in higher cognitive function, parts of which are affected by obesity, is mediated through projections to and from the cerebral cortex. We therefore investigated the relationship between body mass index (BMI) and cerebellocerebral connectivity.

View Article and Find Full Text PDF

Background: Phenylketonuria (PKU) is a rare, hereditary disease that causes disruption in phenylalanine (Phe) metabolism. Despite early intervention, individuals with PKU may have difficulty in several different cognitive domains, including verbal fluency, processing speed, and executive functioning.

Objective: The overarching goal of the Evaluating Fluctuations in Cognitive and Speech Characteristics in Phenylketonuria study (CSP Study) is to characterize the relationships among cognition, speech, mood, and blood-based biomarkers (Phe, Tyr) in individuals with early treated PKU.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!