Parametrically Long Lifetime of Superdiffusion in Nonintegrable Spin Chains
Year: 2024
Type: article
Abstract: Superdiffusion is surprisingly easily observed even in systems without the integrability underpinning this phenomenon. Indeed, the classical Heisenberg chain-one of the simplest many-body systems, and firmly believed to be nonintegrable-evinces a long-lived regime of anomalous, superdiffusive spin dynamics at finite temperature. Similarly, superdiffusion persists for long timescales, even at high temperature, for small perturbations around a related integrable model. Eventually, however, ordinary diffusion is believed to be asymptotically restored. We examine the timescales governing the lifetime of the superdiffusive regime, and argue that it diverges algebraically fast-both in deviation from the integrable limit, and at low temperature, where we find t^{*}∼T^{-ζ} with an exponent possibly as large as ζ=8. This can render the crossover to ordinary diffusion practically inaccessible.
Source: Physical Review Letters
Authors: Adam J. McRoberts, Roderich Moessner
Language: English
Topic: Quantum many-body systems
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,750
Funder: Deutsche Forschungsgemeinschaft
OpenAlex ID: W4405638433