Besides, quantum communication with photons, our lab focusses on quantum computation using the technology of single and entangled photon sources based on spontaneous parametric down conversion in bulk non-linear crystals. We use the single photons and their various degrees of freedom to investigate the various aspects of quantum computation. Current aspects of such an investigation involves the study of qudits leading into higher dimensional quantum computing based on novel spatial degrees of freedom of a single photon.
Quantum Optics describes the study of light and its interactions at a microscopic/quantum level. Single photons are the quantum particles of light. Our lab specialises in the manufacture of single and entangled photons which are then used for quantum optics research at the fundamental level. As a group, we are very interested in investigating Quantum Optical effects and phenomena, by pushing boundaries and extending known effects into the unknown realms. We study different effects like Hanbury-Brown-Twiss Interferometry, Hong-Ou-Mandel Effect as well as intricate nested interferometry using Mach Zehnder and Sagnac geometries for instance, to understand properties of different types of light with a very high accuracy. Our work in pure quantum optics deals with experimental as well as theoretical investigations at very high precision levels, enabling many firsts in terms of discoveries.
Quantum mechanics is a cornerstone of modern physics. Just as the 19th century was called the Machine Age and the 20th century the Information Age, the 21st century promises to go down in history as the Quantum Age. However, can we really claim to fully understand quantum mechanical principles? How much do we really believe of what we know? Answers to such questions require us to revisit the fundamental postulates of quantum mechanics and perform precise theoretical and experimental investigations, in order to come up with the right bounds. In our group, a part of our focus is to attempt such investigations using single light particles i.e. single photons as our tool. Such tests carry a lot of importance in the state-of-the-art theoretical physics scenario where a lot of importance is being given to the unification of quantum mechanics and general relativity. Such unification attempts would also be benefited if one can have a more precise understanding of the principles involved in at least one of the theories i.e. quantum mechanics. Our investigations in this direction include studies of Entanglement dynamics, superposition principle and higher order interference effects as well as weak interaction and quantum measurements.