Introducing Topological Insulators: Mind the Time Reversal
Gregory Tkachov · 2015
This chapter is intended to acquaint the reader with a general notion of topological insulators. The content of the chapter captures the basic ideas and concepts of the pioneering studies of the two- dimensional topological insulators (see Refs. [1-7]) and their three- dimensional counterparts (see Refs. [8-12]). We shall see that the emergence of topological insulators is a vivid example of the importance of fundamental symmetries in physics. In our case, it is the symmetry with respect to the reversal of the direction of time. We, therefore, begin with a discussion of general ideas about time- reversal invariance and its breaking, which will lead us step-by-step to the notion of topological insulators.