Entanglement in a fermion chain under continuous monitoring

Understand

We study the entanglement entropy of the quantum trajectories of a free fermion chain under continuous monitoring of local occupation numbers.

• We propose a simple theory for entanglement entropy evolution from disentangled and highly excited initial states.
• It is based on generalized hydrodynamics and the quasi-particle pair approach to entanglement in integrable systems.
• We test several quantitative predictions of the theory against extensive numerics and find good agreement.