Dynamics of Holographic Entanglement Entropy Following a Local Quench

Understand

We discuss the behaviour of holographic entanglement entropy following a local quench in 2+1 dimensional strongly coupled CFTs.

• The entanglement generated by the quench propagates along an emergent light-cone, reminiscent of the Lieb-Robinson light-cone propagation of correlations in non-relativistic systems.
• We find the speed of propagation is bounded from below by the entanglement tsunami velocity obtained earlier for global quenches in holographic systems, and from above by the speed of light.
• The former is realized for sufficiently broad quenches, while the latter pertains for well localized quenches.