Vaibhav Madhok

There exist instances of computations involving mixed quantum states where the quantum advantages over the best known classical algorithm cannot be ascribed to quantum entanglement. We present a fundamental role played by quantum discord in quantum information processing. One of our main results is a connection between quantum discord and the strong subadditivity of von Neumann entropy. Our second main result gives an operational interpretation of quantum discord by establishing its role in an important class of quantum information protocols. We show that quantum discord measures how coherently one performs the Mother protocol, and its generalization as the FQSW (Fully quantum Slepian Wolf) protocol, in the presence of decoherence.