ABSTRACT
In this chapter, we introduce the reader to the physics of important passive spin-based devices such as sensors and read heads for reading tiny magnetic fields associated with magnetically stored data. Active spin based devices (such as spin transistors) are discussed in the next chapter. The reader is introduced to the concepts of “spin valve,” “giant magnetoresistance,” and the notion of “spin injection efficiency,” which affects the performance of almost every spintronic device extant. This chapter will also familiarize the reader with frequently found terminologies and show that several ideas that may appear unrelated at first are actually interlinked and could be understood in terms of a few simple principles.
