Quantum coherence gained importance in the study of physical phenomenon due to the wave-particle duality. It has been investigated through the study of phase space distributions and higher order correlation functions. But these studies does not allow us to estimate the amount of coherence in the system. Recently in a seminal work by Baumgratz, Cramer and Plenio [Phys. Rev. Lett. 113, 140401 (2014)] a set of principles were laid down to quantify coherence and some possible measures of coherence were introduced. But quantum coherence unlike entanglement can exist in a single qubit apart from the fact that they can exist between two qubits. In the present talk I would like share some developments in this regard from our work [Phy. Rev. Lett 116, 150504 (2016)]. Classifying quantum coherence into local and intrinsic coherence using a metric measure we also connect it to the total coherence of the system via the triangle inequality. The shareability and distribution of the quantum coherence in multipartite systems will be discussed using monogamy relations of coherence. We show the usefulness of our measure of coherence in studying tripartite states like GHZ and W states as well spin chain models. The time evolution dynamics of the local and global coherence and the monogamy of coherence for tripartite system and its usefulness will be discussed in the present talk.
Chandrashekar Radhakrishnan is a Postdoctoral Fellow at NYU-ECNU Institute of Physics and Shanghai New York University in the Quantum Information and Quantum Technology group of Prof. Tim Byrnes. He received his Bachelor in Science from the University of Madras and Masters in Physics from Indian Institute of Technology Madras. His Ph.D was from the Department of Theoretical Physics at the University of Madras and his thesis advisor was Prof. Ranabir Chakrabarti. He worked on Generalized Statistical Mechanics for his Ph.D. His research interests are in the fields of Quantum information, Statistical Mechanics, Condensed Matter physics and Group theory. He has published 10 articles in peer reviewed journals.
Host: Zhiguo Lu