Ultrafast Entanglement Dynamics in Monitored Quantum Circuits

Understand

Projective measurement, a basic operation in quantum mechanics, can induce seemingly nonlocal effects.

• In this work, we analyze such effects in many-body systems by studying the non-equilibrium dynamics of weakly monitored quantum circuits, focusing on entanglement generation and information spreading.
• We find that, due to measurements, the entanglement dynamics in monitored circuits is indeed "faster" than that of unitary ones in several ways.
• Specifically, we find that a pair of well-separated regions can become entangled in a time scale $\ell^{2/3}$, sub-linear in their distance $\ell$.