We study one-dimensional lattices of interacting spins-$\frac{1}{2}$ and show that the effects of quenching the amplitude of a local magnetic field applied to a single site of the lattice can be comparable to the effects of a global perturbation applied instantaneously to the entire system. Both quenches take the system to the chaotic domain, the energy distribution of the initial states approaches a Breit-Wigner shape, the fidelity (Loschmidt echo) decays exponentially, and thermalization becomes viable.

• Received 27 February 2014

DOI:https://doi.org/10.1103/PhysRevE.89.062110