Conclusive and arbitrarily perfect quantum state transfer using amplitude delaying spin chain channels
Daniel Klaus Burgarth, Sougato Bose · arXiv (Cornell University) · 2004
We suggest a protocol for the transfer of quantum information in spin chain channels with a finite recurrence time. By combining a dual-rail encoding with certain measurements at the receiving end, we can get arbitrarily perfect state transfer, i.e. by performing sufficiently many measurements at the receiving end, we can make the probability of perfect state transfer arbitrary 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 in solid state quantum computers. Perfect state transfer with a probability of failure lower than delta in a Heisenberg chain of N spin-1/2 particles can be achieved in a timescale of the order of N^(7/3)*|ln(delta)|. Furthermore, the same scheme can be implemented using a single SU(n) chain which is realizable in quantum dot arrays.