Quantification and characterization of quantum non-Markovianity

Barış Çakmak

Koç University

Abstract: All realistic quantum mechanical systems are in interaction with their surroundings. This inevitable interaction between a system and its environment typically results in the loss of quantum features, such as coherence. One important aspect in the study of these so-called open quantum systems is the concept of non-Markovianity, which arises due to memory effects of the environment. Non-Markovian features might enable the system to recover part of the lost coherence and information back from the environment. Although these memory effects have been investigated in the past, only recently an increase in the understanding of non-Markovianity from a quantum information perspective has emerged.
In this talk, I will briefly introduce the different approaches taken in order to quantify non-Markovianity in quantum systems and introduce an entanglement-based measure of non-Markovianity by employing the concept of assisted knowledge, where the environment, acquires information about a system, by means of its measurement apparatus. The assisted knowledge, based on the accessible information in terms of von-Neumann entropy, monotonically increases in time for all Markovian quantum processes. I will demonstrate that the signatures of non-Markovianity can be captured by the non-monotonic behaviour of the assisted knowledge. Moreover, a clear conceptual relation between the entanglement and mutual information based measures of non-Markovianity in terms of the quantum loss and accessible information will be revealed.

Yer : MSGSÜ Bomonti Binası, Fizik Bölümü
Tarih : 15 Aralık 2016 Perşembe, 15:00