Introduction

In the following video, John Watrous steps you through the content in this lesson on quantum circuits. Alternatively, you can open the YouTube video for this lesson in a separate window.

This lesson introduces the quantum circuit model of computation, which provides a standard way to describe quantum computations.

The lesson also introduces a few important mathematical concepts, including inner products between vectors, the notions of orthogonality and orthonormality, and projections and projective measurements, which generalize standard basis measurements. Through these concepts, we'll derive fundamental limitations on quantum information, including the no-cloning theorem and the impossibility to perfectly discriminate non-orthogonal quantum states.