Nanoscale devices are distinguishable from the larger microscale devices in their specific dependence on physical phenomena and effects that are central to their operation. The size change manifests itself through changes in importance of the phenomena and effects that become dominant and the changes in scale of underlying energetics and response. Examples of these include classical effects such as single electron effects, quantum effects such as the states accessible as well as their properties; ensemble effects ranging from consequences of the laws of numbers to changes in properties arising from different magnitudes of the inter-actions, and others. These interactions, with the limits placed on size, make not just electronic, but also magnetic, optical and mechanical behavior interesting, important and useful. Connecting these properties to the behavior of devices is the focus of this textbook. Description of the book series: This collection of four textbooks in the Electroscience series span the undergraduate-to-graduate education in electrosciences for engineering and science students. It culminates in a comprehensive under-standing of nanoscale devices—electronic, magnetic, mechanical and optical in the 4th volume, and builds to it through volumes devoted to underlying semiconductor and solid-state physics with an emphasis on phenomena at surfaces and interfaces, energy interaction, and fluctuations; a volume devoted to the understanding of the variety of devices through classical microelectronic approach, and an engineering-focused understanding of principles of quantum, statistical and information mechanics. The goal is provide, with rigor and comprehensiveness, an exposure to the breadth of knowledge and interconnections therein in this subject area that derives equally from sciences and engineering. By completing this through four integrated texts, it circumvents what is taught ad hoc and incompletely in a larger number of courses, or not taught at all. A four course set makes it possible for the teaching curriculum to be more comprehensive in this and related advancing areas of technology. It ends at a very modern point, where researchers in the subject area would also find the discussion and details an important reference source.