Photonic Simulation of Entanglement Growth After a Spin Chain Quench

Understand

The time evolution of quantum many-body systems is one of the least understood frontiers of physics.

• The most curious feature of such dynamics is, generically, the growth of quantum entanglement with time to an amount proportional to the system size (volume law) even when the interactions are local.
• This phenomenon, unobserved to date, has great ramifications for fundamental issues such as thermalisation and black-hole formation, while its optimisation clearly has an impact on technology (e.g., for on-chip quantum networking).
• Here we use an integrated photonic chip to simulate the dynamics of a spin chain, a canonical many-body system.