Recent years have witnessed tremendous progress in laboratory experiments for quantum computing. As the complexity of these experiments increases, however, so too does the difficultly in verifying the quality of the experiment by some objective measure, and in characterizing any undesired noise processes therein so as to improve the next generation devices. In particular, in the absence of a full-fledged quantum computer, we are left with the question: how can we tell if our quantum computer is really working? In this tutorial I will present an overview of the core methods that experimentalists use to address these tasks. The two main tools can be broadly classified as being either tomography or randomized benchmarking, and I will discuss the strengths and weaknesses of these methods. I will describe the theoretical challenges that remain both for mathematical analysis of these ideas as well as for practical data analysis from real experiments.

свернуть