  Quantum information science is an exciting, wide, rapidly progressing,
cross-disciplinary field, and that very nature makes it both attractive and
hard to enter. In this primer, we first provide answers to the three essential
questions that any newcomer needs to know: How is quantum information
represented? How is quantum information processed? How is classical information
extracted from quantum states? We then introduce the most basic quantum
information theoretic notions concerning entropy, sources, and channels, as
well as secure communications and error correction. We conclude with examples
that illustrate the power of quantum correlations. No prior knowledge of
quantum mechanics is assumed.
