This book discusses the elementary ideas and tools needed for open quantum systems in a comprehensive manner. The emphasis is given to both the traditional master equation as well as the functional (path) integral approaches. It discusses the basic paradigm of open systems, the harmonic oscillator and the two-level system in detail. The traditional topics of dissipation and tunneling, as well as the modern field of quantum information, find a prominent place in the book. Assuming a basic background of quantum and statistical mechanics, this book will help readers familiarize with the basic tools of open quantum systems.

Open quantum systems is the study of quantum dynamics of the system of interest, taking into account the effects of the ambient environment. It is ubiquitous in the sense that any system could be envisaged to be surrounded by its environment which could naturally exert its influence on it. Open quantum systems allows for a systematic understanding of irreversible processes such as decoherence and dissipation, of the essence in order to have a correct understanding of realistic quantum dynamics and also for possible implementations. This would be essential for a possible development of quantum technologies.

Autorentext
SUBHASHISH BANERJEE is an assistant professor and head of the Department of Physics, Indian Institute of Technology Jodhpur, India. He obtained his PhD degree from the School of Physical Sciences, Jawaharlal Nehru University, New Delhi, India, in 2003. He has been involved in the study of the quantum theory of open systems since his PhD. A major theme of his work has been to see how the theory of open quantum systems provides a common umbrella to understand various facets of quantum optics, quantum information processing, quantum computing, quantum cryptography, the foundations of quantum mechanics, relativistic quantum mechanics and field theory. He has published two books and more than 67 articles in national and international journals of repute. 

Inhalt
**?Chapter 1**. Introduction.- Chapter 2. A Primer on Quantum Statistical Mechanics and Path Integrals.- Chapter 3. Master Equations: A Prolegomenon to Open Quantum Systems.- Chapter 4. Influence Functional Approach to Open Quantum Systems.- Chapter 5. Dissipative Harmonic Oscillator.- Chapter 6. Dissipative Two-State System.- Chapter 7. Quantum Tunneling.- Chapter 8. Open Quantum System at Interface with Quantum Information.- Chapter 9. Recent Trends.