This book aims to cover the UGC curriculum of physics for quantum physics. Designed for BSc (Hons) and MSc in Physics it will also serve as a useful text/reference for students of chemistry. The text lays emphasis on physical concepts with details of necessary mathematical steps. The salient features of the book include clear presentation of concepts student-friendly approach solved examples tables and illustrations for better understanding of the concepts and questions at the end of each chapter. This is the thoroughly revised edition which includes new topics such as Physical significance of spherical harmonics field and coordinates of the field Lagrangian formulation for the field commutation relations for field operators• quantisation of nonrelativistic Schrodinqer field• the neutral Klein Gordon field the Dirac field the neutral Klein Gordon field in terms of plane waves• the charged KG field the Einstein-Podolsky-Rosen problem and the Aharonov-Bohm Effect.