NAQUAS: Non-equilibrium dynamics in Atomic systems for QUAntum Simulation

Recent progress in various areas of physics has demonstrated our ability to control quantum effects in customized systems and materials, thus paving the way for a promising future for quantum technologies. The emergence of such quantum devices, however, requires one to understand fundamental problems in non-equilibrium statistical physics, which can pave the way towards full control of quantum systems, thus reinforcing new applications and providing innovative perspectives. This project is dedicated to the study and the control of out-of-equilibrium properties of quantum many-body systems which are driven across phase transitions. Among several approaches, it will mainly focus on slow quenches and draw on the understanding delivered by the Kibble-Zurek (KZ) mechanism. This rather simple paradigm connects equilibrium with out-of-equilibrium properties and constitutes a benchmark for scaling hypothesis. It could pave the way towards tackling relevant open questions, which lie at the heart of our understanding of out-of-equilibrium dynamics and are key issues for operating in a robust way any quantum simulator. Starting from this motivation, we will test the limits of validity of the KZ dynamics by analyzing its predictions, thus clarifying its predictive power, and extend this paradigm to quantum critical systems with long-range interactions and to topological phase transitions. We will combine innovative theoretical ideas of condensed-matter physics, quantum optics, statistical physics and quantum information, with advanced experiments with ultracold atomic quantum gases. Quantum gases are a unique platform for providing model systems with the level of flexibility and control necessary for our ambitious goal. Their cleanness and their robustness to decoherence will greatly enhance the efficient interplay between theory and experiments, and provide a platform of studies whose outcomes are expected to have a strong scientific impact over a wide range of disciplines. On the short time scale we will exploit this knowledge to develop viable protocols for quantum simulators. In general, we expect that the results of this project will lay the ground for the development of the next generation of quantum devices and simulators.

Our studies will contribute to develop a systematic understanding of non-equilibrium statistical mechanics, a truly interdisciplinary field of science relevant, to mention just a few, to biology and to the dynamics of financial markets. Specifically, our studies will complement and extend our understanding of the dynamical behavior of many-body systems at criticality. Indeed, a recent example taken from our own work is the observation of a turbulent cascade in a controlled setting of an ultracold gas which links and sheds light on the non-equilibrium dynamics and turbulence phenomena. We foresee that many such insights will be produced within our Consortium.

Our proposed work lies within the "Quantum Technologies" theme. More specifically, by providing a deeper understanding and direct control of out-of-equilibrium phenomena in quantum many-body systems, we will make impactful contributions to the areas of "Quantum simulation" and "Quantum metrology, sensing and imaging".

For example, by developing novel concepts and strategies, we will contribute to the development of robust and viable quantum simulators. On the basis of the insight we will gain on, we will also devise strategies and means to implement robust approaches, based on engineering the external potential, customizing the driving control fields, and tuning the interactions. Our final results will provide a relevant toolbox of knowledge and expertise for quantum technological applications.

This project will also have a large transformational impact on technology and society. A significant part of the requested funding is devoted to hire personnel (Postdocs, and in some non-UK nodes, also PhD students). Training high-level and highly motivated young researchers in world-leading international scientific teams collaborating across different European nodes is a crucial step for the success of the European-level Quantum technologies flagship, which is closely connected to the recently-founded UK Quantum Technology nodes. During our project we will give a robust formation to this new generation of "quantum engineers". They will become future industry leaders and policy-makers in the ever-more (quantum-)technology-driven world and they will spread their knowledge and training to the industrial community. For instance, the advanced numerical modelling skills or training in optics and electronics obtained by young scientists through this project are highly sought-after transferrable skills beyond academia. Examples of international companies that have hired our recent students and postdocs include Microsoft, Mathworks, Saint-Gobain, Areva, Safran, General Electric, Comsol, Motorola, etc. Our laboratories are also strongly connected to the emergence of high-technology start-ups that ensure the transfer of technology from the academic world towards society.

This work is also linked to quantum computing through (i) the need to control the time evolution of quantum systems which is central to quantum simulation and to quantum computing and (ii) the role of topology in quantum physics which leads to rich and complex many-body states accessible with quantum simulation and which paves the way to topologically protected quantum computing.