Published in:Journal of Physics A: Mathematical and Theoretical
Language:
Not determined
DOI:
10.1088/1751-8121/ad3c82
ISSN:
1751-8113;
1751-8121
Origination:
Footnote:
Description:
<jats:title>Abstract</jats:title>
<jats:p>Unital qubit Schwarz maps interpolate between positive and completely positive maps. It is shown that the relaxation rates of the qubit semigroups of unital maps enjoying the Schwarz property satisfy a universal constraint, which provides a modification of the corresponding constraint known for completely positive semigroups. As an illustration, we consider two paradigmatic qubit semigroups: Pauli dynamical maps and phase-covariant dynamics. This result has two interesting implications: it provides a universal constraint for the spectra of qubit Schwarz maps and gives rise to a necessary condition for a Schwarz qubit map to be Markovian.</jats:p>