Building quantum computers a practical introduction

"This chapter briefly introduces the origins, elements, and fundamental themes of quantum computers. In Section 1.1 we recount how successive observations by different scientists led to the concept of quantum computing. We also review the potential applications that propelled quantum computing from a nascent idea to a global enterprise. Section 1.2 distinguishes quantum computers from classical ones and outlines the five criteria for quantum computing. We introduce the standard model of quantum computation - the circuit model - in Section 1.3. Next, we explain why it's believed that quantum computers are (1) more powerful than classical ones (Section 1.4); and (2) physically realizable (Section 1.5)"--