Closed expressions for one-qubit states of convex roof coherence
measures
- URL: http://arxiv.org/abs/2308.03116v1
- Date: Sun, 6 Aug 2023 13:51:46 GMT
- Title: Closed expressions for one-qubit states of convex roof coherence
measures
- Authors: Xiao-Dan Cui and C. L. Liu
- Abstract summary: We present the analytical expressions for the convex roof coherence measures for one-qubit states.
Measures include the coherence of formation, the coherence measure coherence, the coherence rank.
- Score: 0.0
- License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
- Abstract: We study the closed expressions of the convex roof coherence measures for
one-qubit states in this paper. We present the analytical expressions for the
convex roof coherence measures, $C_f(\rho)$, of one-qubit states with
$C_f(\varphi):=f(\abs{c_0}^2,\abs{c_1}^2)$ (where
$\ket{\varphi}=c_0\ket{0}+c_1\ket{1}$) being convex with respect to the $l_1$
norm of coherence of $\varphi$ (i.e., $C_{l_1}(\varphi)$), such coherence
measures including the coherence of formation, the geometric measure of
coherence, the coherence concurrence, and the coherence rank. We further
present the operational interpretations of these measures. Finally, we present
the usefulness of the convex roof coherence measures $C_f(\varphi)$ being
non-convex with respect to $C_{l_1}(\varphi)$ by giving the necessary and
sufficient conditions for the transformations
$p\varphi_1\oplus(1-p)\varphi_2\to q\phi_1\oplus(1-q)\phi_2$ via incoherent
operations, where $\varphi_i$, $\phi_j$ $(i, j=1, 2)$ are one-qubit pure states
and $0\leq p, q\leq 1$.
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