Observation of many-body scarring in a Bose-Hubbard quantum simulator

The ongoing quest for understanding nonequilibrium dynamics of complex quantum systems underpins the foundation of statistical physics as well as the development of quantum technology. Quantum many-body scarring has recently opened a window into novel mechanisms for delaying the onset of thermalization by preparing the system in special initial states, such as the Z2 state in a Rydberg atom system. Here we realize many-body scarring in a Bose-Hubbard quantum simulator from previously unknown initial conditions such as the unit-filling state. We develop a quantum-interference protocol for measuring the entanglement entropy and demonstrate that scarring traps the many-body system in a low-entropy subspace. Our work makes the resource of scarring accessible to a broad class of ultracold-atom experiments, and it allows one to explore the relation of scarring to constrained dynamics in lattice gauge theories, Hilbert space fragmentation, and disorder-free localization.

Automated summary

The ongoing quest for understanding nonequilibrium dynamics of complex quantum systems has led to the discovery of quantum many-body scarring. This phenomenon allows for the delay of thermalization by preparing the system in special initial states. In this study, the researchers demonstrate many-body scarring in a Bose-Hubbard quantum simulator, using previously unknown initial conditions. This work opens up new possibilities for exploring the relationship between scarring and various quantum phenomena.