We study the dynamics and thermalization of strongly correlated fermions in finite one-dimensional lattices after a quantum quench. Our calculations are performed using exact diagonalization. We focus on one- and two-body observables such as the momentum distribution function $\left[n\left(k\right)\right]$ and the density-density structure factor $\left[N\left(k\right)\right]$, respectively, and study the effects of approaching an integrable point. We show that while the relaxation dynamics and thermalization of $N\left(k\right)$ for fermions is very similar to the one of hardcore bosons, the behavior of $n\left(k\right)$ is distinctively different. The latter observable exhibits a slower relaxation dynamics in fermionic systems. We identify the origin of this behavior, which is related to the off-diagonal matrix elements of $n\left(k\right)$ in the basis of the eigenstates of the Hamiltonian. More generally, we find that thermalization occurs far away from integrability and that it breaks down as one approaches the integrable point.

• Received 20 August 2009

DOI:https://doi.org/10.1103/PhysRevA.80.053607