Hydrodynamic long-time tails after a quantum quench

Understand

After a quantum quench, a sudden change of parameters, generic many particle quantum systems are expected to equilibrate.

• A few collisions of quasiparticles are usually sufficient to establish approximately local equilibrium.
• Reaching global equilibrium is, however, much more difficult as conserved quantities have to be transported for long distances to build up a pattern of fluctuations characteristic for equilibrium.
• Here we investigate the quantum quench of the one-dimensional bosonic Hubbard model from infinite to finite interaction strength U using semiclassical methods for weak, and exact diagonalization for strong quenches.