Entanglement transition from variable-strength weak measurements

By Marcin Szyniszewski, Alessandro Romito, H. Schomerus. Physical review B, 2019

223 citations recorded by the source corpus.

We show that weak measurements can induce a quantum phase transition of interacting many-body systems from an ergodic thermal phase with a large entropy to a nonergodic localized phase with a small entropy, but only if the measurement strength exceeds a critical value. We demonstrate this effect for a one-dimensional quantum circuit evolving under random unitary transformations and generic positive operator-valued measurements of variable strength. As opposed to projective measurements describing a restricted class of open systems, the measuring device is modeled as a continuous Gaussian probe, capturing a large class of environments. By employing data collapse and studying the enhanced fluctuations at the transition, we obtain a consistent phase boundary in the space of the measurement strength and the measurement probability, clearly demonstrating a critical value of the measurement strength below which the system is always ergodic, irrespective of the measurement probability. These findings provide guidance for quantum engineering of many-body systems by controlling their environment.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/472810aa1a5f91b2874bdb5c0b7936b237e54b17

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Artificial Intelligence

1. A. Nahum
2. Matthew Fisher
3. V. Khemani
4. B. Skinner
5. D. Huse
6. J. Ruhman
7. S. Vijay
8. Yaodong Li

In Atomic and Molecular Physics, and Optics

1. A. Nahum
2. Matthew Fisher
3. V. Khemani
4. D. Huse
5. Yaodong Li
6. B. Skinner
7. Tianci Zhou
8. J. Ruhman

In Statistical and Nonlinear Physics

1. A. Nahum
2. V. Khemani
3. Tianci Zhou
4. J. Ruhman
5. B. Skinner
6. Sthitadhi Roy
7. Matthew Fisher
8. S. Vijay

Citations in the corpus

• Statistical mechanics of quantum error correcting codes (2020, background): “It would be interesting to see if the entanglement domain wall picture is valid in a broader class of models, such as hybrid random Haar circuits [13, 19, 20, 22, 56] or other “generic” models of non-unitary dynamics [57–66], or circuit models with measurements only [40, 67–69].”
• Random Quantum Circuits (2022, background): “Numerical evidence for this transition has by now been found in a wide range of microscopic models (52, 53, 58, 68, 65, 66, 61, 62, 54, 63, 64, 77, 67).”
• Entanglement Membrane in Chaotic Many-Body Systems (2019, background): “The effective spin model may also be extended to dynamics with measurement, or other types of interaction with an environment, for example to clarify the relationship between different universality classes of measurement-induced criticality [78, 79, 83–93].”
• Dynamical Purification Phase Transition Induced by Quantum Measurements (2019, background): “[29, 30, 41, 51]).”
• Measurement-induced entanglement phase transition on a superconducting quantum processor with mid-circuit readout (2022, methodology): “005 [18], which are in good qualitative agreement with our value ν ≈ 2.”
• Measurement and Entanglement Phase Transitions in All-To-All Quantum Circuits, on Quantum Trees, and in Landau-Ginsburg Theory (2020, background): “In the many-body case this random dynamics admits a “measurement phase transition” (MPT) between two qualitatively different, stable dynamical phases, with distinct entanglement properties [6–27].”