  We propose a strategy for perfect state transfer in spin chains based on the
use of an unmodulated coupling Hamiltonian whose coefficients are explicitly
time dependent. We show that, if specific and non-demanding conditions are
satisfied by the temporal behavior of the coupling strengths, our model allows
perfect state transfer. The paradigma put forward by our proposal holds the
promises to set an alternative standard to the use of clever encoding and
coupling-strength engineering for perfect state transfer.

Quantum Physics