Kinetics of information scrambling in correlated electrons: disorder-driven transition from shock-wave to FKPP dynamics

Abstract

Quenched disorder slows down the scrambling of quantum information. Using a bottom-up approach, we formulate a kinetic theory of scrambling in a correlated metal near a superconducting transition, following the scrambling dynamics as the impurity scattering rate is increased. Within this framework, we rigorously show that the butterfly velocity $v$ is bounded by the light cone velocity $v_{\mathrm{lc}}$ set by the Fermi velocity. We analytically identify a disorder-driven dynamical transition occurring at small but finite disorder strength between a spreading of information characterized at late times by a discontinuous shock wave propagating at the maximum velocity $v_{\mathrm{lc}}$, and a smooth traveling wave belonging to the Fisher or Kolmogorov-Petrovsky-Piskunov (FKPP) class and propagating at a slower, if not considerably slower, velocity $v$. In the diffusive regime, we establish the relation $v^2/{\lambda }_{\mathrm{FKPP}}\sim D_{\mathrm{el}}$ where ${\lambda }_{\mathrm{FKPP}}$ is the Lyapunov exponent set by the inelastic scattering rate and $D_{\mathrm{el}}$ is the elastic diffusion constant.

$4+\epsilon$ pages plus 15 pages of Appendix. Minor modifications (published version)

References in corpus (7)

• Slow scrambling in disordered quantum systems
• Microscopic model of quantum butterfly effect: out-of-time-order correlators and traveling combustion waves
• Thermal diffusivity and chaos in metals without quasiparticles
• Scrambling in Random Unitary Circuits: Exact Results
• Hydrodynamic theory of scrambling in chaotic long-range interacting systems
• Out-of-time-ordered correlator in the one-dimensional Kuramoto-Sivashinsky and Kardar-Parisi-Zhang equations
• Traveling discontinuity at the quantum butterfly front

Cited by in corpus (2)

• Control of spatiotemporal chaos by stochastic resetting
• Quantum Thermalization via Travelling Waves