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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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The control of quantum systems is limited by unwanted interactions with the environment and uncertainties in the applied control fields. For ions these uncertainties include unwanted fluctuations in the intensity and the frequency of the electromagnetic field used to control the qubit. For unknown but static errors on the time scale of the experiment, compensating composite pulses sequences can be used to minimize the effect of these errors. In this talk, I will describe the general method of compensating composite pulse sequences for single qubit and multi-qubit systems. I will then discuss two experiments performed in collaboration with GTRI using composite pulse sequences. The first experiment uses known pulse sequences to effectively reduce the spatial variation in a microwave field. The second experiment tests a family of narrowband composite pulse sequences that we have developed. Narrowband pulse sequences can improve ion addressing in a chain by minimizing the effective rotation on neighboring ions. The new pulse sequences are an improvement in both sequence time and cross talk minimization.