The Dual Roles of Quantum Discord in a Non-demolition Probing Task
arXiv:1307.1194 · doi:10.1103/PhysRevA.87.022113
Abstract
We present a non-demolition quantum information processing task of probing the information of a class of quantum state. In this task, the information is extracted by some unitary evolution with the introduced probing qubit assisted, but the probed quantum state (density matrix) is undisturbed at any time and independent of the choice of the initial probing state. We give a sufficient and necessary condition on the Hamiltonian that can lead to the successful realization of such a task. We prove that, for any feasible scheme, the probed plus probing system will always stay at a disentangled state with one side quantum discord absent and the other side one inevitably produced in the probing process. An explicit example is given for the demonstration, whilst the example shows that the ratio of quantum discord to the total correlation will have to reduce to zero for the maximal accessible information. In this sense, we say that quantum discord plays the dual roles in this case.
5 pages and 1 figure
References in corpus (18)
- Quantum discord and the power of one qubit
- Necessary and sufficient condition for non-zero quantum discord
- Experimental quantum computing without entanglement
- Robustness of quantum discord to sudden death
- Classical and quantum correlations under decoherence
- No-local-broadcasting theorem for quantum correlations
- Interpreting quantum discord through quantum state merging
- Operational interpretations of quantum discord
- On the role of entanglement and correlations in mixed-state quantum computation
- All non-classical correlations can be activated into distillable entanglement
- Operational Significance of Discord Consumption: Theory and Experiment
- Conservation law for distributed entanglement of formation and quantum discord
- Entanglement irreversibility from quantum discord and quantum deficit
- Frozen discord in non-Markovian dephasing channels
- Broadcast copies reveal the quantumness of correlations
- Quantum discord as a resource in quantum communication
- Quantum Communication in Spin Systems With Long-Range Interactions
- Direct Measure of Quantum Correlation
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