What makes a process quantum? A sequential measurement perspective

by Andrea Smirne (University of Milan)

Tuesday 24 Mar 2026, 14:00 → 16:00 Europe/Rome

Grassano (Roma Tor Vergata)

 More than a century after the advent of quantum theory, the question of which properties and phenomena are genuinely quantum—meaning they cannot be replicated by any classical theory—remains a subject of active investigation. In this talk, I will explore how and to what extent non-classicality can be rigorously associated with specific features in the evolution of open quantum systems subjected to sequential measurements over time. I will first revisit the general framework for defining multi-time correlators in open quantum systems and introduce the Kolmogorov consistency conditions that characterize classical stochastic processes, and serve as a tool for distinguishing classical from quantum multi-time statistics, in the same spirit as the Leggett-Garg inequalities. I will then present recent findings that relate the emergence of non-classicality to the dynamics of quantum coherences within the system, or to quantum correlations between the system and its environment, depending on whether the underlying process is Markovian or non-Markovian.