Controlling measurement-induced phase transitions with tunable detector coupling

Quantum 9, 1697 (2025).

https://doi.org/10.22331/q-2025-04-08-1697

We study the evolution of a quantum many-body system driven by two competing measurements, which induces a topological entanglement transition between two distinct area law phases. We employ a positive operator-valued measurement with variable coupling between the system and detector within free fermion dynamics. This approach allows us to continuously track the universal properties of the transition between projective and continuous monitoring. Our findings suggest that the percolation universality of the transition in the projective limit is unstable when the system-detector coupling is reduced.