Run-and-Tumble Dynamics and Zeno--Anti-Zeno Transition in Biased Quantum Trajectories

Abstract

We identify the transition from the oscillatory Rabi regime to the localized Zeno/Anti-Zeno regime in continuous measurement and feedback of a qubit as a quantum analogue of Motility-Induced Phase Separation (MIPS). A mapping between a biased monitored qubit and a classical ``Run-and-Tumble" active particle is studied. We demonstrate that the competition between coherent Rabi driving (analogous to active motility) and measurement-induced feedback bias (analogous to persistence) mimics the behavior of biological swimmers. This framework provides a picture of measurement-induced phase transitions using the language of active matter and offering a novel pathway for designing dissipative noisy quantum systems.