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Experimental generation of quantum discord via noisy processes
B P Lanyon1, P Jurcevic1, C Hempel1
1Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, Technikerstrasse 21A, 6020 Innsbruck, Austria and Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria.
Physical Review Letters
|August 29, 2014
Summary
Noise can create quantum discord, a nonclassical correlation, even in unentangled systems. This study reveals how environmental noise, even acting on one qubit, generates quantum discord, differing from entanglement.
Area of Science:
- Quantum Information Science
- Quantum Optics
- Quantum Many-Body Systems
Background:
- Quantum systems in mixed states can exhibit nonclassical correlations quantified by quantum discord, even when unentangled.
- Quantum discord is a potential resource for quantum information processing tasks.
- Understanding the role of noise in generating quantum correlations is crucial for quantum technologies.
Purpose of the Study:
- To investigate the capability of environmental noise to generate quantum discord between two ionic qubits.
- To explore the types of discordant states that can be generated by different noise processes.
- To differentiate between quantum discord and entanglement in the context of noise.
Main Methods:
- Precisely controlling the interaction of two ionic qubits with their environment.
- Applying noise selectively to one or both quantum systems.
- Analyzing the correlation matrices of the generated quantum states.
Main Results:
- Noise acting on a single quantum system can generate quantum discord between two systems.
- States generated by single-system noise are limited in their correlation matrix rank.
- Classically correlated noise processes can generate a wider range of discordant states with arbitrary correlation matrix rank.
Conclusions:
- Environmental noise can automatically generate nonclassical correlations (quantum discord) in quantum systems.
- Quantum discord and entanglement are fundamentally different phenomena, with noise playing a distinct role in their generation.
- The findings have implications for understanding and utilizing quantum correlations in realistic noisy quantum devices.
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