A note on coherence power of N-dimensional unitary operators

M. García-Díaz; D. Egloff; M. B. Plenio

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arXiv · 1510.06683

A note on coherence power of N-dimensional unitary operators

M. García-Díaz·D. Egloff·M. B. Plenio

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Abstract

The coherence power of a quantum channel, that is, its ability to increase the coherence of input states, is a fundamental concept within the framework of the resource theory of coherence. In this note we discuss various possible definitions of coherence power. Then we prove that the coherence power of a unitary operator acting on a qubit, computed with respect to the $l_1$-coherence measure, can be calculated by maximizing its coherence gain over pure incoherent states. We proceed to show that this result fails for dimensions N>2, that is, the maximal coherence gain is found when acting on a state with non-vanishing coherence.

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M. García-Díaz, D. Egloff, M. B. Plenio. 2015-10-22. A note on coherence power of N-dimensional unitary operators. https://arxiv.org/abs/1510.06683

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