  The three- spin chain with Heisenberg XY- interaction is simulated in a
three- qubit nuclear magnetic resonance (NMR) quantum computer. The evolution
caused by the XY- interaction is decomposed into a series of single- spin
rotations and the $J$- coupling evolutions between the neighboring spins. The
perfect state transfer (PST) algorithm proposed by M. Christandl et al [Phys.
Rev. Lett, 92, 187902(2004)] is realized in the XY- chain.
