  We suggest a protocol for perfect quantum communication through spin chain
channels. By combining a dual-rail encoding with measurements only at the
receiving end, we can get conclusively perfect state transfer, whose
probability of success can be made arbitrarily close to unity. As an example of
such an amplitude delaying channel, we show how two parallel Heisenberg spin
chains can be used as quantum wires. Perfect state transfer with a probability
of failure lower than P in a Heisenberg chain of N spin-1/2 particles can be
achieved in a timescale of the order of N^1.7|ln(P)|. We demonstrate that our
scheme is more robust to decoherence and non-optimal timing than any scheme
using single spin chains.
