Weakly driven quantum symmetries

ongoing

The DrumS project will establish a new paradigm for stabilizing exotic non-thermal states by weakly driving quantum many-body systems. Present research theoretically predicts peculiar non-thermal states in fine-tuned models with additional symmetries, for example, in integrable models with macroscopically many conservation laws. However, these models and their exact symmetries cannot be accurately realized in solid-state experiments. My hypothesis is that weak driving can boost the underlying symmetries in realistic setups and have a substantial effect on quantities protected by approximate symmetries, for example, on approximately conserved operators. The basic idea can be illustrated with a greenhouse, where windows ensure approximate conservation of energy. A weak driving by sun can have a considerable effect as it only compensates for the weak losses and stabilizes a high temperature that is not proportional to the drive. The ambitious goal of DrumS is to demonstrate that a strong response to a weak drive is a generic property of setups where driving compensates for weak symmetry breaking perturbations and stabilizes large expectation values of potentially useful quantities. While state of the art studies consider detrimental effects of perturbations, DrumS will turn approximate symmetries into a resource for novel out-of-equilibrium phenomena and technological applications. The theoretical program will promote the practical significance of fascinating idealized models, such as integrable, many-body localized, and lattice gauge theories. Driving protocols will compensate unavoidable integrability and gauge breaking to realize peculiar energy, spin and particle transport or synchronize resonant states into a superconducting response. DrumS will grow a new branch of non-linear phenomena, with exciting possibilities for realization in condensed matter experiments, synthetic quantum simulators, and other areas of physics where symmetries play a fundamental role.