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Quantum systems evolving unitarily and subject to quantum measurements exhibit various types of non-equilibrium phase transitions, arising from the competition between unitary evolution and measurements. Dissipative phase transitions in steady states of time-independent Liouvillians and measurement induced phase transitions at the level of quantum trajectories are two primary examples of such transitions. Investigating a many-body spin system subject to periodic resetting measurements, we argue that many-body dissipative Floquet dynamics provides a natural framework to analyze both types of transitions. We show that a dissipative phase transition between a ferromagnetic ordered phase and a paramagnetic disordered phase emerges for long-range systems as a function of measurement probabilities. A measurement induced transition of the entanglement entropy between volume law scaling and sub-volume law scaling is also present, and is distinct from the ordering transition. The two phases correspond to an error-correcting and a quantum-Zeno regimes, respectively. The ferromagnetic phase is lost for short range interactions, while the volume law phase of the entanglement is enhanced. An analysis of multifractal properties of wave function in Hilbert space provides a common perspective on both types of transitions in the system. Our findings are immediately relevant to trapped ion experiments, for which we detail a blueprint proposal based on currently available platforms.
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This content will become publicly available on June 17, 2026
A unified picture for quantum Zeno and anti-Zeno effects
The quantum Zeno effect is a striking feature of quantum mechanics with foundational implications and practical applications in quantum control, error suppression, and error correction. The effect has branched off into a variety of different interpretations, making it easy to miss the unifying features of the underlying effect. In particular, the quantum Zeno effect has been studied in the context of both selective and nonselective measurements; for both pulsed and continuous interactions; for suppression and enhancement of decay (Zeno / anti-Zeno effects); and even in the absence of measurement entirely. This concise review presents a unified picture of these effects by examining how they all arise in the context of a driven qubit subjected to measurements or dissipation. Zeno and anti-Zeno effects are revealed as regimes of a unified effect that appears whenever a measurement-like process competes with a non-commuting evolution. The current landscape of Zeno and anti-Zeno effects is reviewed through this unifying lens, with a focus on experimental applications and implementations. The quantum Zeno effect is found to be both ubiquitous and essential for the future of near-term quantum computing.
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- PAR ID:
- 10603968
- Publisher / Repository:
- arXiv preprint
- Date Published:
- Journal Name:
- arXivorg
- ISSN:
- 2331-8422
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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