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Quantum coherence sets the quantum speed limit for mixed states

Abstract We cast observable measure of quantum coherence as a resource to control the quantum speed limit (QSL) for unitary evolutions. For non-unitary evolutions, QSL depends on that of the state of the system and environment together. We show that the product of the time bound and the coherence (asymmetry) or the quantum part of the uncertainty behaves in a geometric way under partial elimination and classical mixing of states. These relations give a new insight into the quantum speed limit. We also show that our bound is experimentally measurable and is tighter than various existing bounds in the literature.

Retrieving and routing quantum information in a quantum network

In extant quantum secret sharing protocols, once the secret is shared in a quantum network (qnet) it cannot be retrieved, even if the dealer wishes that his/her secret no longer be available in the network. For instance, if the dealer is part of the two qnets, say

A study of teleportation and super dense coding capacity in remote entanglement distribution

{\mathcal {Q}}_1

Complementarity of quantum correlations in cloning and deleting of quantum states

Q1 and

Coherence of quantum channels

{\mathcal {Q}}_2

Mutual uncertainty, conditional uncertainty, and strong subadditivity

Q2 and he/she subsequently finds that