Coherence makes quantum systems ‘magical’

Abstract

Two primary facets of quantum technological advancement that hold great\npromise are quantum communication and quantum computation. For quantum\ncommunication, the canonical resource is entanglement. For quantum gate\nimplementation, the resource is 'magic' in an auxiliary system. It has already\nbeen shown that quantum coherence is the fundamental resource for the creation\nof entanglement. We argue on the similar spirit that quantum coherence is the\nfundamental resource when it comes to the creation of magic. This unifies the\ntwo strands of modern development in quantum technology under the common\nunderpinning of existence of quantum superposition, quantified by the coherence\nin quantum theory. We also attempt to obtain magic monotones inspired from\ncoherence monotones and vice versa. We further study the interplay between\nquantum coherence and magic in a qutrit system and that between quantum\nentanglement and magic in a qutrit-qubit setting.\n