Tunable Superdiffusion in Integrable Spin Chains Using Correlated Initial States

Phys Rev Lett. 2024 Apr 26;132(17):176303. doi: 10.1103/PhysRevLett.132.176303.

Abstract

Although integrable spin chains host only ballistically propagating particles, they can still feature diffusive charge transfer. This diffusive charge transfer originates from quasiparticle charge fluctuations inherited from the initial state's magnetization Gaussian fluctuations. We show that ensembles of initial states with quasi-long-range correlations lead to superdiffusive charge transfer with a tunable dynamical exponent. We substantiate our prediction with numerical simulations and discuss how finite time and finite size effects might cause deviations.