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Bell Diagonal and Werner State Generation: Entanglement, Non-Locality, Steering and Discord on the IBM Quantum
Elias Riedel Gårding1,2, Nicolas Schwaller1, Chun Lam Chan3
1Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
Entropy (Basel, Switzerland)
|July 2, 2021
Summary
We developed novel quantum circuits to create Bell diagonal states (BDS) and tested their quantum correlations. Our findings reveal a new inequality relating quantum discord measures for these states.
Area of Science:
- Quantum Information Science
- Quantum Computing
- Quantum Correlations
Background:
- Bell diagonal states (BDS) are crucial for understanding quantum correlations.
- Previous methods for generating BDS were limited or complex.
- Characterizing quantum correlations requires robust experimental techniques.
Purpose of the Study:
- To propose and implement the first correct special-purpose quantum circuits for preparing Bell diagonal states (BDS).
- To experimentally characterize complex quantum correlations of BDS in their full parameter space.
- To investigate theoretical relationships between different quantum discord measures.
Main Methods:
- Design of novel, special-purpose quantum circuits for BDS preparation.
- Implementation of circuits on the IBM Quantum computer.
- Experimental evaluation of entanglement, non-locality, steering, and discord using quantum tomography.
Main Results:
- Successful generation of the entire class of Bell diagonal states (BDS).
- Comprehensive experimental characterization of quantum correlations, including entanglement, concurrence, CHSH non-locality, steering, and discord.
- Validation of theoretical predictions for quantum correlation measures over the full parameter space.
Conclusions:
- The proposed quantum circuits provide an effective method for generating and studying Bell diagonal states (BDS).
- The study establishes a new general inequality between quantum discord and asymmetric relative entropy of discord.
- For all Bell diagonal states, quantum discord and asymmetric relative entropy of discord are proven to be equal.
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