QUROPE Quantum Information Processing and Communication in Europe

Controlling the interaction of a single quantum system with its environment is a fundamental challenge in quantum science and technology. In this publication, the group of Ronald Hanson at TU-Delft managed to strongly suppress the coupling of a single spin in diamond with the surrounding spin bath by using double-axis dynamical decoupling. The coherence was preserved for arbitrary quantum states, as verified by quantum process tomography. The resulting coherence time enhancement followed a general scaling with the number of decoupling pulses. No limit was observed for the decoupling action up to 136 pulses, for which the coherence time was enhanced more than 25 times compared to that obtained with spin echo. The results obtained uncover a new regime for experimental quantum science allowing the group to overcome a major hurdle for implementing quantum information protocols.

G. de Lange, Z. H. Wang, D. Ristè, V. V. Dobrovitski and R. Hanson
Science 330, 60 (2010)
http://www.sciencemag.org/content/330/6000/60.abstract