Efficient simulation and design of quantum CONtrol sTRategies for mAny-Body quAntum SystemS (CONTRABASS)

We are witnessing a phase of intense development of modern quantum technologies, able to exploit fundamental properties of quantum mechanics, such as superposition and entanglement, to accomplish tasks that are without reach via classical means. The development of control strategies for open quantum systems is of paramount importance to counteract the noise that prevents these quantum technologies from reaching their ultimate performances. On the other hand, to simulate many-body open quantum systems is an incredibly demanding task, making the design and assessment of control strategies in technologically relevant quantum protocols even more challenging. Our project "efficient simulation and design of quantum CONtrol sTRategies for mAny-Body quAntum SystemS" (CONTRABASS) will tackle this problem as follows: i) It will explore the usefulness of numerical techniques based on deep reinforcement learning to optimize measurement and feedback strategies. In particular, CONTRABASS will first focus on quantum state engineering and quantum metrology tasks. ii) It will develop novel numerical techniques for the simulation of many-body open quantum systems, by merging Quantum Monte Carlo variational approaches with stochastic unravelings of master equations. iii) It will finally combine these two approaches with the aim of devising and assessing advanced quantum control strategies for atomic ensembles with a focus on their quantum metrological applications. Atomic ensembles are inherently many-body quantum systems, and the interaction with a high-finesse optical cavity can be exploited to perform monitoring and feedback, with the goal of preparing resourceful (spin-squeezed) states for quantum sensing. Furthermore, we will seek a proof-of-principle experimental verification of the developed strategies and numerical methods, in a cavity-enhanced optical clock with ultracold Strontium atoms.