Adjusting phase-covariant qubit channel performance with non-unitality

Autor:	Katarzyna Siudzińska, Michał Studziński
Rok vydání:	2023
Předmět:	Statistics and Probability Modeling and Simulation General Physics and Astronomy Statistical and Nonlinear Physics Mathematical Physics
Zdroj:	Journal of Physics A: Mathematical and Theoretical. 56:205301
ISSN:	1751-8121 1751-8113
DOI:	10.1088/1751-8121/acccbf
Popis:	We analyze quantum communication properties of phase-covariant channels depending on their degree of non-unitality. In particular, we derive analytical formulas for the minimal and maximal channel fidelity on pure states and maximal output purity. Next, we introduce a measure of non-unitality and show how to manipulate between unital and maximally non-unital maps by considering classical mixtures of quantum channels. Finally, we prove that maximal fidelity and maximal output purity increase with non-unitality and present several examples. Interestingly, non-unitality can also prolong quantum entanglement and lead to its rebirth.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::34e8862aabcffa81227f2e232db7cf7e https://doi.org/10.1088/1751-8121/acccbf Zobrazit plný text záznamu