Invariance of quantum correlations under local channel for a bipartite quantum state
1 Department of Physics, University of Amran - Amran, Yemen
2 Department of Physics, University of Pune - Pune, India-411007
Received: 21 December 2012
Accepted: 19 June 2013
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.
PACS: 03.65.Yz – Decoherence; open systems; quantum statistical methods / 03.65.Db – Functional analytical methods / 03.65.Ud – Entanglement and quantum nonlocality (e.g. EPR paradox, Bell's inequalities, GHZ states, etc.)
© EPLA, 2013