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A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
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Experimental entanglement activation from discord in a programmable quantum measurement
Gerardo Adesso1, Vincenzo D'Ambrosio2, Eleonora Nagali2
1School of Mathematical Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
Physical Review Letters
|April 29, 2014
Summary
Observing quantum systems alters their state, revealing quantum discord. This study shows local observation can convert quantum discord into distillable entanglement, a powerful quantum correlation, between the system and the measurement apparatus.
Area of Science:
- Quantum Information Science
- Quantum Mechanics
- Experimental Physics
Background:
- Quantum mechanics dictates that observation is an active process, not passive.
- Measurements on one quantum particle (B) in a two-particle system (A, B) typically alter the combined state (AB).
- Local measurements reveal unique correlations called quantum discord between quantum systems.
Purpose of the Study:
- To experimentally demonstrate that local observation can activate quantum discord.
- To show this activation converts quantum discord into distillable entanglement.
- To investigate the role of quantum discord in generating entanglement.
Main Methods:
- Utilized a flexible two-photon experimental setup.
- Implemented a three-qubit system (A, B, M) to model quantum particles and a measurement apparatus.
- Programmed initial correlations, measurement interactions, and characterization processes.
Main Results:
- Demonstrated that the act of local observation can serve as an activation protocol.
- Showed the conversion of quantum discord into distillable entanglement between the measurement apparatus (M) and the composite system (AB).
- Established a direct link between local observation, quantum discord, and entanglement generation.
Conclusions:
- The act of observing the quantum world fundamentally involves interactions that can generate entanglement.
- Quantum discord is a valuable resource that can be converted into distillable entanglement through local observation.
- This work highlights the potential of quantum discord as a key resource in quantum information processing and entanglement generation.
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