Dephasing and the steady state in quantum many-particle systems

Understand

We discuss relaxation in bosonic and fermionic many-particle systems.

• For integrable systems, the time evolution can cause a dephasing effect, leading for finite subsystems to certain steady states.
• We give an explicit derivation of those steady subsystem states and devise sufficient prerequisites for the dephasing to take place.
• We also find simple scenarios, in which dephasing is ineffective and discuss the dependence on dimensionality and criticality.