Many-body Dynamical Delocalization and Many-body Anderson Metal-Insulator Transition with Kicked Ultracold Quantum Gases

Understanding the interplay of interactions and disorder in quantum transport poses long-standing fundamental challenges for both theory and experiment. We utilize a synthetic momentum lattice platform using ultracold quantum gases kicked by pulsed optical lattices, to experimentally investigate this problem. Using periodic kicks, we simulate the 1D Anderson model in momentum-space and observe the interaction-driven emergence of dynamical delocalization and many-body quantum chaos [1]. The observed dynamics feature sub-diffusive energy growth and sheds light on the evolution of dynamically localized states in the presence of many-body interactions, which has long remained an open question. Using quasi-periodic kicks, we experimentally investigate the role of many-body interactions in the 3D Anderson metal-insulator transition. We observe and characterize interaction-driven delocalization of a non-universal sub-diffusive nature in the insulator regime of the non-interacting phase diagram, corresponding to an interaction-induced shift of the metal-insulator transition boundary [2]. Our results shed light on interaction-driven transport phenomena in quantum many-body systems, in a regime where theoretical approaches are extremely challenging and provide conflicting predictions.

[1] J. See Toh, K. McCormick, X. Tang, Y. Su, X. Luo, X, Zhang, and S. Gupta, Nature Physics 18, 1297 (2022).

[2] J. See Toh et al. in prep.