  We explore the non-equilibrium response of Chern insulators. Focusing on the
Haldane model, we study the dynamics induced by quantum quenches between
topological and non-topological phases. A notable feature is that the Chern
number, calculated for an infinite system, is unchanged under the dynamics
following such a quench. However, in finite geometries, the initial and final
Hamiltonians are distinguished by the presence or absence of edge modes. We
study the edge excitations and describe their impact on the
experimentally-observable edge currents and magnetization. We show that,
following a quantum quench, the edge currents relax towards new equilibrium
values, and that there is light-cone spreading of the currents into the
interior of the sample.
