Overcoming ambiguities in classical and quantum correlation measures
arXiv:1408.1562 · doi:10.1209/0295-5075/108/10003
Abstract
We identify ambiguities in the available frameworks for defining quantum, classical, and total correlations as measured by discordlike quantifiers. More specifically, we determine situations for which either classical or quantum correlations are not uniquely defined due to degeneracies arising from the optimization procedure over the state space. In order to remove such degeneracies, we introduce a general approach where correlations are independently defined, escaping therefore from a degenerate subspace. As an illustration, we analyze the trace-norm geometric quantum discord for two-qubit Bell-diagonal states.
5 pages, 2 figures. v2: Minor corrections. Published version
References in corpus (8)
- Necessary and sufficient condition for non-zero quantum discord
- Interpreting quantum discord through quantum state merging
- Quantum discord bounds the amount of distributed entanglement
- Quantum cost for sending entanglement
- Quantum resources for hybrid communication via qubit-oscillator states
- Global quantum correlations in finite-size spin chains
- Quantum-correlating power of local quantum channels
- Unifying approach to the quantification of bipartite correlations by Bures distance