A. Bermudez1, P. O. Schmidt2, M. B. Plenio1, and A. Retzker1
1Institut für Theoretische Physik, Albert-Einstein Allee 11, Universität Ulm, 89069 Ulm, Germany
2QUEST Institute, Physikalisch-Technische Bundesanstalt and Leibniz University Hannover, 38116 Braunschweig, Germany
We introduce a scheme that combines phonon-mediated quantum logic gates in trapped ions with the benefits of continuous dynamical decoupling. We demonstrate theoretically that a strong driving of the qubit decouples it from external magnetic-field noise, enhancing the fidelity of two-qubit quantum gates. Moreover, the scheme does not require ground-state cooling, and is inherently robust to undesired ac Stark shifts. The underlying mechanism can be extended to a variety of other systems where a strong driving protects the quantum coherence of the qubits without compromising the two-qubit couplings.
Reference: 
Phys. Rev. A 85, 040302(R) (2012)