Error correction requires control over greater numbers of qubits than have previously been independently manipulated in a single system. To gain many-qubit control, we require a method to optically address many ions simultaneously. As a path toward meeting this challenge, Duke University has developed micro-electro-mechanical system (MEMS) mirrors that have been demonstrated to control multiple optical beams appropriate for addressing individual ions. More information on these MEMS can be found in references [1-3] below.
Concurrently, we are investigating the use of a multi-channel acousto-optic modulator (AOM). Advantages could include reduced optical phase error between qubits, fast switching, and less beam profile distortion. This is a joint effort between Duke, University of Maryland, and Harris, Inc.
 Kim, Changsoon, Caleb Knoernschild, Bin Liu, and Jungsang Kim. IEEE Journal of selected topics in Quantum Electronics 13, 322 (2007).
 Knoernschild, Caleb, Changsoon Kim, Bin Liu, Felix P. Lu, and Jungsang Kim. Optics letters 33 273 (2008).
 Crain, S., E. Mount, S. Baek, and J. Kim. Applied Physics Letters 105, 181115 (2014).