2000/05/17 by Yehuda Sharf, Timothy F. Havel, David G. Cory · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physreva.62.052314
published as Phys. Rev. A 62(2000), 052314. · Postscript only (19 pages, 5 figures)
arxiv created 2000/05/17 · arxiv updated 2009/12/01
Quantum information processing by liquid-state NMR spectroscopy uses pseudo-pure states to mimic the evolution and observations on true pure states. A new method of preparing pseudo-pure states is described, which involves the selection of the spatially labeled states of an ancilla spin with which the spin system of interest is correlated. This permits a general procedure to be given for the preparation of pseudo-pure states on any number of spins, subject to the limitations imposed by the loss of signal from the selected subensemble. The preparation of a single pseudo-pure state is demonstrated by carbon and proton NMR on 13C-labeled alanine. With a judicious choice of magnetic field gradients, the method further allows encoding of up to 2N pseudo-pure states in independent spatial modes in an N+1 spin system. Fast encoding and decoding schemes are demonstrated for the preparation of four such spatially labeled pseudo-pure states.