CDQT Guest Seminar: Phase transitions in quantum control landscapes

Guest Seminar hosted by Collective Dynamics and Quantum Transport Unit
Speaker:  Nicolò Beato (Max Planck Institute for the Physics of Complex Systems)
Title: "Phase transitions in quantum control landscapes"

Abstract:

Modern quantum technologies require the efficient control of quantum dynamics. Optimal Control Theory provides the formal framework to address this challenge by optimizing a control strategy to satisfy experiment-dependent requirements (e.g., preparation of physically interesting quantum states or minimization of physical observables). In this framework, the optimization procedure amounts to finding global minima of a high-dimensional cost function (control landscape), which assigns a figure of merit to each possible control strategy.
In this talk, I will focus on abrupt transitions occurring in the cost function landscape upon varying the control duration. A prime example is the Quantum Speed Limit, which sets the minimum time required for a quantum system to evolve between two states. I will discuss analytical and numerical methods designed to unravel the connection between (i) structural changes in the cost function and (ii) non-analytic points in statistical order parameters defined for near-to-optimal control strategies.

 

About the speaker:

Nicolò Beato completed his undergraduate studies in theoretical physics at the University of Insubria (Como, Italy), including a six-month Erasmus period at KU Leuven (Belgium). He is currently pursuing a PhD at the Max Planck Institute for the Physics of Complex Systems in Dresden (Germany), where his research focuses on control problems in closed and open quantum systems.