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arXiv:1209.5035 · Europhysics Letters (EPL)

Invariance of quantum correlations under local channel for a bipartite quantum state

Ali Saif M. Hassan, Pramod S. Joag

Published Jul 1, 2013• 5 citations
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Abstract

We show that the quantum discord in a bipartite quantum state is invariant under the action of a local quantum channel if and only if the channel is invertible. We also show that the geometric measure of discord is preserved under the action of a local channel if the channel is invertible and if the metric used to define the geometric discord is monotonic. In particular, both versions of quantum discord are invariant under a local unitary channel.

DOI
10.1209/0295-5075/103/10004

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We show that the quantum discord in a bipartite quantum state is invariant under the action of a local quantum channel if and only if the channel is invertible. We also show that the geometric measure of discord is preserved under the action of a local channel if the channel is invertible and if the metric used to define the geometric discord is monotonic. In particular, both versions of quantum discord are invariant under a local unitary channel.
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