My name is Fernando Gago and I am a PhD student at the Freie Universität Berlin where I work on quantum optimal control. I obtained my Master’s degree at Universidad Complutense de Madrid, where I got my background in optimal control theory applied to quantum systems thanks to a collaboration done at the CSIC (Spanish national research council). My Master’s thesis involved some work with Krotov’s optimization algorithm and with superconducting qubits, delving into the implementation of quantum gates in transmons.

Currently I am doing my research under the supervision of Prof. Dr. Christiane Koch. In our projects we explore the capabilities of optimization algorithms applied to quantum systems with a control. In particular we are interested in applying this methods to quantum sensing, where a quantum system is prepared in a specific state to maximally interact with a physical magnitude, thus letting us retrieve the information from that interaction and effectively allowing us to measure said magnitude. For this, the initial states need to be very accurately prepared, and that is the reason why we need to use our optimization algorithms.

On a parallel project, we study the concept of quantum speed limit applied to an open quantum system, i.e. the minimum time in which we can force a quantum system to evolve into a previously defined final state. For this purpose, we use controllability theory, which combines purely mathematical results with physical concepts to estimate this quantity. Not only does this shed some light on the system properties, but it will also give some insight regarding the fastest and most natural evolutions for each quantum system.

- H. Goerz, D. Basilewitsch, F. Gago-Encinas, M. G. Krauss, K. P. Horn, D. M. Reich, C. P. Koch. “Krotov: A Python implementation of Krotov’s method for quantum optimal control.” SciPost Phys. 7, 080 (2019)