Entanglement spreading after a geometric quench in quantum spin chains

Understand

We investigate the entanglement spreading in the anisotropic spin-1/2 Heisenberg (XXZ) chain after a geometric quench.

• This corresponds to a sudden change of the geometry of the chain or, in the equivalent language of interacting fermions confined in a box trap, to a sudden increase of the trap size.
• The entanglement dynamics after the quench is associated with the ballistic propagation of a magnetization wavefront.
• At the free fermion point (XX chain), the von-Neumann entropy S_A exhibits several intriguing dynamical regimes.