Abstract

In recent years, the thermalization of quantum systems has been the subject of intense study. Particularly interesting are systems which exhibit slow or completely arrested thermalization, with many-body localized systems being a prime example of the latter. Recent theoretical work has identified Hilbert space fragmentation in clean, kinetically-constrained systems as another mechanism for the breakdown of ergodicity in many-body quantum systems. Motivated by engineering such systems with ultracold atoms, I will discuss two recent experiments we have performed. In the first, we studied tilted Fermi-Hubbard systems and discovered a slow thermalization mechanism due to an interplay of charge and heat transport. Modified versions of this system may be used to explore prethermal Hamiltonians with a fragmented Hilbert space. In the second experiment, we studied the short-time quench dynamics of charge-density wave states in a spinless fermionic lattice gas with off-site interactions realized with Rydberg-dressing. We again observed a slowdown of the dynamics for strong, off-site interactions. We discuss connections of this experiment to theoretical work on fragmentation in t-V models.