Modern Quantum Mechanics, Why We Need it, How to Use it?

Abstract

A new field of research centered on quantum science and technology is emerging. This rapidly developing field deals with the study and control of single quantum entities, i.e. atoms, ions, photons, which are no longer isolated but are parts of a larger system. Manipulation of these quantum entities forms the basis of modern quantum technology, from quantum computation to quantum communication and quantum sensing. One, therefore, needs to reconsider the basic concepts of state, evolution, and measurement for these so-called open quantum systems. This is a pedagogical review paper on the rudiments of modern quantum mechanics, which keeps citations to the literature to a minimum and assumes only a knowledge of elementary quantum mechanics. It is meant to prepare the reader for studying the modern research papers at the forefront of this field.