Exact relaxation to Gibbs and non-equilibrium steady states in the quantum cellular automaton Rule 54

Understand

We study the out-of-equilibrium dynamics of the quantum cellular automaton Rule 54 using a time-channel approach.

• We exhibit a family of (non-equilibrium) product states for which we are able to describe exactly the full relaxation dynamics.
• We use this to prove that finite subsystems relax to a one-parameter family of Gibbs states.
• We also consider inhomogeneous quenches.