Year: 2026
Type: preprint
Abstract: Recent advances in quantum simulation have enabled the discovery of novel forms of universality in quantum many-body dynamics. In this Review, we discuss deep thermalization and Hilbert space ergodicity--two recently discovered phenomena characterized by the emergence of distributions of quantum states that are "maximally random" in a precise sense. They offer a new perspective on how irreversible statistical mechanics arises from reversible unitary quantum dynamics, going beyond conventional theories of quantum thermalization and equilibration. We review a unifying framework, rooted in quantum information theory and principles of maximum entropy, that explains the different forms of ergodicity which arise under various physical constraints. We discuss open questions and active research directions, including generalizations beyond ensembles of pure quantum states, phase transitions in deep thermalization tied to deeper forms of ergodicity-breaking, connections to broader topics in quantum thermalization and ergodicity, and applications in quantum information science, such as for benchmarking or tomography.
Source: arXiv (Cornell University)
Language: English
Topic: Quantum many-body systems
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, U.S. Department of Energy, National Research Foundation Singapore, Centre for Quantum Technologies, Office of Science, Multidisciplinary University Research Initiative, Institute for Quantum Information and Matter, California Institute of Technology, Center for Ultracold Atoms, Massachusetts Institute of Technology, Advanced Scientific Computing Research, Army Research Office
Awards: G149988304, G1797871914, G2403330605, QLCI-CI: NSF Quantum Leap Challenge Institute for Present and Future Quantum Computing, G3209459412, G3266171376, Center: Institute for Quantum Information and Matter: IQIM, The Institute for Quantum Information and Matter: Advancing the Entanglement Frontier, CAREER: Probing Quantum Matter using Programmable Quantum Simulators, G5884252700, G6020731938, G6048591767, G6512472947, G6906965799, Center for Ultracold Atoms, G7252073159, Center: Center for Ultracold Atoms
OpenAlex ID: W7214319259