QIS in Physics: Momentum Space Quantum Simulation: Many-body Dynamics of a Kicked Quantum Gas

The synthetic dimension of momentum space can be utilized for quantum simulation with ultracold neutral atoms, where lattice sites are coupled through multi-photon optical transitions with controlled on-site energies and inter-site tunneling. This platform offers technical advantages over its position-space counterpart e.g. ease of detection and ease of varying dimension number, while also altering the form of inter-atomic interactions. We will discuss our observation of interaction-driven breakdown of dynamical localization (momentum space equivalent of Anderson localization) in a 1D ultracold bosonic gas periodically kicked by an optical lattice [1]. The observed dynamics indicates the onset of many-body quantum chaos and features sub-diffusive energy growth. In synthetic dimensions d > 2, the system is a simulator for the Anderson metal-insulator transition, and we will also discuss our observations of many-body delocalization in the corresponding insulator phase. These results shed light on interaction-driven transport phenomena in quantum many-body systems, in a regime where theoretical approaches can be challenging.

[1] J. See Toh et al. Many-body dynamical delocalization in a kicked one-dimensional ultracold gas. Nat. Phys. 18, 1297 (2022)