Entanglement in dual unitary quantum circuits with impurities

Understand

Bipartite entanglement entropy is one of the most useful characterizations of universal properties in a many-body quantum system.

• Far from equilibrium, there exist two highly effective theories describing its dynamics -- the quasiparticle and membrane pictures.
• In this work we investigate entanglement dynamics, and these two complementary approaches, in a quantum circuit model perturbed by an impurity.
• In particular, we consider a dual unitary quantum circuit containing a spatially fixed, non-dual-unitary impurity gate, allowing for differing local Hilbert space dimensions to either side.