Gonzalo A. Álvarez, Alexandre M. Souza, and Dieter Suter
Fakultät Physik, Technische Universität Dortmund, Dortmund, Germany
Received 1 March 2012; published 29 May 2012
The loss of quantum information due to interactions with external degrees of freedom, which is known as decoherence, remains one of the main obstacles for large-scale implementations of quantum computing. Accordingly, different measures are being explored for reducing its effect. One of them is dynamical decoupling DD which offers a practical solution because it only requires the application of control pulses to the system qubits. Starting from basic DD sequences, more sophisticated schemes were developed that eliminate higher-order terms of the system-environment interaction and are also more robust against experimental imperfections. A particularly successful scheme, called concatenated DD CDD, gives a recipe for generating higher-order sequences by inserting lower-order sequences into the delays of a generating sequence. Here, we show how this scheme can be improved further by converting some of the pulses to virtual and thus ideal pulses. The resulting scheme, called (XY4)^n, results in lower power deposition and is more robust against pulse imperfections than the original CDD scheme.
©2012 American Physical Society