Quantum simulation of far-from-equilibrium gauge-theory dynamics

• Applicant: Dr. Jad Halimeh
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields ; Theoretical Condensed Matter Physics
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 519873523

The main subject of my current work is concentrated around the out-of-equilibrium dynamics and quantum simulation of gauge theories, which are fundamental quantum many-body models with local gauge symmetries that encode the laws of nature through local constraints between matter and gauge fields. Achieving large-scale quantum simulators of gauge theories and stabilizing and controlling their out-of-equilibrium dynamics is an outstanding challenge whose accomplishment will allow probing some of the most fundamental questions of nature on accessible table-top quantum devices. In particular, I am interested in two fronts: (i) understanding and technologically leveraging the out-of-equilibrium dynamics of these models as relevant to both high-energy and condensed matter physics, and (ii) devising controlled and reliable realizations of gauge theories on modern quantum simulators through rigorous theoretical frameworks. Although there has been impressive progress on these two fronts, there are still major open questions. On the first front, these include thermalization or lack thereof in gauge theories, the confinement-deconfinement transition, string breaking in higher spatial dimensions, the nature of disorder-free localization in gauge theories and its relation to orthodox many-body localization, the gauge-theoretic origin of quantum many-body scars, staircase prethermalization and its connection to the dynamical renormalization of Gauss's law, to name a few. Research into these questions is of fundamental importance in allowing us to better understand how quantum many-body models in general, and gauge theories in particular, behave out of equilibrium, and has the promising prospect of facilitating applications in quantum information technologies. On the second front, despite impressive progress, there remains a lot to do in terms of the quantum simulation of gauge theories. While important proof-of-principle experiments have demonstrated the simulation of gauge symmetries on small building blocks, large-scale simulations of gauge fields coupled to dynamical matter beyond the simplest gauge groups remain to be implemented. The holy grail of gauge theories, quantum chromodynamics with its SU(3) non-Abelian gauge symmetry, is still a long way to implement on a realistic large-scale quantum simulator. Quantum simulators dedicated to the simulation of gauge theories have the real potential to surpass classical methods, and therefore advancing this technology is of great significance.

• DFG Programme: Independent Junior Research Groups