Dynamics, criticality, and universality
in random quantum circuits

Scientific Report: Dynamics, Criticality, and Universality in Random Quantum Circuits

Michael Gullans, Princeton University, Department of Physics, Princeton, New Jersey, 08540 USA & Joint Center for Quantum Information and Computer Science, NIST/University of Maryland, College Park, Maryland 20742, USA

Jedediah Pixley, Department of Physics and Astronomy, Center for Materials Theory, Rutgers University, Piscataway, New Jersey 08854, USA

Romain Vasseur, Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, USA

Justin Wilson, Department of Physics and Astronomy, Center for Materials Theory, Rutgers University, Piscataway, New Jersey 08854, USA

The workshop Dynamics, criticality, and universality in random quantum circuits was a successful, virtual conference. We chose speakers from condensed matter and quantum information to both foster communication in a rapidly developing field. The focus of the workshop was random quantum circuits, which all speakers spoke on, and in particular, the measurement-driven phase transition. As we learned in the course of this conference, this phase transition draws interest for its critical nature, mappings to statistical mechanics models, relation to quantum error correcting codes, and experimental applications in quantum simulators and quantum computing systems.

There was very lively discussion throughout the conference. The most important participants were the speakers and discussion session leaders, who actively contributed to all the discussions. We received positive feedback from many participants who enjoyed the ample opportunity for discussion created by the conference format. The discussions tended to be at a high level of expertise and delved into many important issues relevant for the topic.

Scientific newcomers played an important role in the workshop primarily through their posters and questions within discussion sections. The experts and established participants contributed heavily to the virtual discussion, allowing for in-depth and exciting scientific discussions. We encourage MPI to get feedback from participants if possible, to improve the format for virtual meetings and poster sessions.

In light of the challenges with a virtual format, the workshop was an overall success in our view. The workshop brought together leaders in quantum information science and condensed matter physics, fostering interdisciplinary discussions and activities. The workshop put the study of random quantum circuits into a broader context and helped clarify the scientific motivation for pursuing these problems. Several participants expressed gratitude for the timeliness of this workshop. The opportunity for a larger group to discuss and dissect much of this will undoubtedly lead to new work and collaborations within this field. Some general open questions that came out of the discussions and talks are listed below. We hope that the coming years see continued progress on these questions.

  • How do we define universality classes and classify different phases for dynamical phase transitions in random circuit models?
  • What are the possible experimental realizations of monitored nonequilibrium quantum many-body systems?
  • Can noisy random circuits still have quantum computational advantage in near-term devices?
  • Can we prepare volume-law entangled phases of matter in a fault-tolerant manner?