Tobias Micklitz

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We discuss a real-time path-integral framework for capturing the unitary dynamics of chaotic many-body quantum systems that effectively act as their own environment. Extending the field theory of chaotic or disordered single-particle systems to the many-body regime, this approach describes a broad class of systems and disorder models beyond perturbation theory in inverse Hilbert space dimension. It offers a microscopic and non-perturbative account of thermalization dynamics across all relevant timescales: from initial short-time scattering processes, through the onset of ergodicity at an effective Thouless time, and up to the many-body Heisenberg time. Applied to systems such as random circuit networks, the theory captures the dynamical buildup of both entanglement and entropy, providing a unified description of the crossover from initial product states to fully ergodic, maximum-entropy states.

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CBPF Rio de Janeiro
InnoDom Cologne, Weyertal 109, 50931 Köln
Contact: Sebastian Diehl, Simon Trebst