Decay of long-lived oscillations after quantum quenches in gapped interacting quantum systems
Physical Review A American Physical Society (APS) 109:3 (2024) 032208
Divergent nonlinear response from quasiparticle interactions
Physical Review Letters American Physical Society 131 (2023) 256505
Abstract:
We demonstrate that nonlinear response functions in many-body systems carry a sharp signature of interactions between gapped low-energy quasiparticles. Such interactions are challenging to deduce from linear response measurements. The signature takes the form of a divergent-in-time contribution to the response – linear in time in the case when quasiparticles propagate ballistically – that is absent for free bosonic excitations. We give a physically transparent semiclassical picture of this singular behaviour. While the semiclassical picture applies to a broad class of systems we benchmark it in two simple models: in the Ising chain using a form-factor expansion, and in a nonintegrable model — the spin-1 AKLT chain — using time-dependent density matrix renormalization group (tDMRG) simulations. We comment on extensions of these results to finite temperatures.A short introduction to Generalized Hydrodynamics
Physica A Statistical Mechanics and its Applications Elsevier 631 (2023) 127572
Statistics of matrix elements of local operators in integrable models
ArXiv 2307.1241 (2023)