Bell Correlations in a Many-Body System with Finite Statistics
Sebastian Wagner1, Roman Schmied2, Matteo Fadel2
1Quantum Optics Theory Group, Department of Physics, University of Basel, Klingelbergstrasse 82, 4056 Basel, Switzerland.
Physical Review Letters
|December 9, 2017
Summary
This study explores the statistical requirements for detecting Bell correlations in many-body systems. Researchers developed new methods to identify these quantum correlations using fewer measurements and less spin squeezing.
Area of Science:
- Quantum Information Science
- Many-Body Physics
- Quantum Foundations
Background:
- Recent experiments demonstrated the first violation of a Bell correlation witness in a many-body system.
- Detecting Bell-correlated states in complex quantum systems requires specific statistical analysis.
Purpose of the Study:
- To determine the necessary statistics for witnessing Bell-correlated states in many-body systems.
- To develop improved Bell inequality witnesses for multipartite systems.
Main Methods:
- Derivation of multipartite Bell inequalities with arbitrary measurement settings and one- and two-body correlators.
- Construction of improved witnesses utilizing two collective measurements.
- Establishment of an upper bound on required statistics.
Main Results:
- Developed novel Bell inequalities applicable to multipartite systems.
- Introduced improved witnesses capable of detecting Bell correlations with minimal spin squeezing.
- Quantified the statistical bounds for confirming Bell-correlated states.
Conclusions:
- The developed witnesses offer a more efficient method for detecting Bell correlations in many-body systems.
- These findings provide a clearer understanding of the statistical requirements for quantum correlation experiments.
- The work potentially enables the detection of Bell correlations in states with significantly reduced spin squeezing.
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