Continuing the exceptional tradition of the previous editions, Quantum Mechanics, Fourth Edition provides essential information about atomic and subatomic systems and covers some modern applications of the field. Supported by a Web page that contains a bibliography, color versions of some of the illustrations, and links to other relevant sites, the book shows how cutting-edge research topics of quantum mechanics have been applied to various disciplines. It first demonstrates how to obtain a wave equation whose solutions determine the energy levels of bound systems. The theory is then made more general and applied to a number of physical examples. Later chapters describe the connection between relativity and quantum mechanics, give some examples of how quantum mechanics has been used in information processing, and, finally, discuss the conceptual and philosophical implications of the subject. New to the Fourth Edition:A chapter on quantum information processing that includes applications to the encryption and de-encryption of coded messagesA chapter on relativistic quantum mechanics and introductory quantum field theoryUpdated material on the conceptual foundations of quantum physics containing discussions of non-locality, hidden variables, and parallel universesExpanded information on tunneling microscopy and the Bose-Einstein condensate Presenting up-to-date information on the conceptual and philosophical aspects of quantum mechanics, this revised edition is suitable both for undergraduates studying physics, chemistry, or mathematics and for researchers involved in quantum physics.