Christian O. Bretschneider (1), Gonzalo A. Álvarez (2), Gershon Kurizki (1), and Lucio Frydman (1)
(1) Department of Chemical Physics, Weizmann Institute of Science, Rehovot, 76100, Israel
(2) Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
Received 13 September 2011; published 3 April 2012
We show that coupled-spin network manipulations can be made highly effective by repeated projections of the evolving quantum states onto diagonal density-matrix states (populations). As opposed to the intricately crafted pulse trains that are often used to fine-tune a complex network’s evolution, the strategy hereby presented derives from the “quantum Zeno effect” and provides a highly robust route to guide the evolution by destroying all unwanted correlations (coherences). We exploit these effects by showing that a relaxationlike behavior is endowed to polarization transfers occurring within a N-spin coupled network. Experimental implementations yield coupling constant determinations for complex spin-coupling topologies, as demonstrated within the field of liquid-state nuclear magnetic resonance.
© 2012 American Physical Society