Information Dynamics in Random Quantum Circuits

Determining where the information flows is of fundamental importance in understanding quantum many-body physics. In chaotic systems, information spreads into entangled form, showing non-trivial dynamics, including the light-cone structure and the scrambling phenomenon. The detailed process between these two cases is less well-understood and involves rich phenomena. In this talk, I will discuss our two works on information dynamics in random quantum circuits, one of the minimally structured models that capture generic chaotic behavior. In our first work, we adopt infinitely long circuits and discover phase transitions in the information retrieved from different final probe regions. In the other one, we study the full-time dynamics of information and discover a rich set of dynamical phase transitions in the information flow. Such dynamical phase transitions vary with the initial position where the information is located and the final probe region, showing ubiquitous behaviors. These results will help us better understand the information propagation and scrambling in this quantum many-body model.