"Universal properties of relaxation rates for the irreversible dynamics of open quantum systems"
Prof. Dariusz Chruscinski
Institute of Physics, Nicolaus Copernicus University, Torun (Poland)

Thursday 22/2/2024 16:00
Aula A, Dipartimento di Fisica
Live streaming: Teams link

Open quantum systems, namely quantum systems in weak interaction with their environment, evolve irreversibly as manifested by typical relaxation rates, a general property of which is reviewed. It turns out that for a fairly large class of irreversible quantum dynamics, relaxation rates satisfy an intricate constraint which provides a generalization of the well known relation between transversal and longitudinal rates for 2-level systems. It is conjectured that this constraint is universal, i.e., it is valid for all quantum dynamical semigroups. The conjecture is strongly supported by numerical analysis. Moreover, it is shown that the conjectured constraint is tight. Since relaxation rates (or equivalently relaxation times) are often measured in the laboratory, this universality may be considered as a physical manifestation of complete positivity, a structural request necessary for physical consistency. The conjecture has also interesting implications: it provides a universal constraint for the spectra of quantum channels and gives rise to necessary conditions for Markovian channels.