Asymptotic Properties for Markovian Dynamics in Quantum Theory and General Probabilistic Theories

Abstract

We address asymptotic decoupling in the context of Markovian quantum dynamics. Asymptotic decoupling is an asymptotic property on a bipartite quantum system, and asserts that the correlation between two quantum systems is broken after a sufficiently long time passes. The first goal of this paper is to show that asymptotic decoupling is equivalent to local mixing which asserts the convergence to a unique stationary state on at least one quantum system. In the study of Markovian dynamics, mixing and ergodicity are fundamental properties which assert the convergence and the convergence of the long-time average, respectively. The second goal of this paper is to show that mixing for dynamics is equivalent to ergodicity for the two-fold tensor product of dynamics. This equivalence gives us a criterion of mixing that is a system of linear equations. All results in this paper are proved in the framework of general probabilistic theories (GPTs), but we also summarize them in quantum theory.