Quantum Nature of Light and the Photon

Quantum Nature of Light and the Photon

K Thyagarajan,
(Retired Professor of Physics, IIT Delhi, New Delhi)
Department of Physics, Bennett University, Greater Noida, UP

 

Classical electromagnetism describes light in the form of waves consisting of oscillating electric and magnetic fields. However there are many observations where this simple picture fails and one needs to use the quantum theory of light from where the concept of photon emerges. The talk will bring out the necessity of a quantum theory to describe light and being out some interesting quantum states of light such as single photon superposition states and entangled states. A short introduction to an important method to generate such states will be described followed by some recent applications in the area of quantum information science and technology.