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Measuring entanglement in condensed matter systems.
M Cramer1, M B Plenio, H Wunderlich
1Institut für Theoretische Physik, Albert-Einstein Allee 11, Universität Ulm, Ulm, Germany.
Physical Review Letters
|March 17, 2011
Summary
Researchers developed a new method to quantify entanglement in many-body systems using only standard experimental techniques. This approach bypasses the need for full state characterization, enabling direct study of quantum correlations.
Area of Science:
- Quantum Physics
- Condensed Matter Physics
- Atomic Physics
Background:
- Quantifying entanglement in many-body systems is crucial for understanding quantum correlations.
- Previous methods required full state characterization, posing a significant experimental challenge.
- Genuine quantum correlations in complex systems have been difficult to study directly.
Purpose of the Study:
- To develop a novel, experimentally accessible method for quantifying entanglement in spin and cold atom many-body systems.
- To remove the obstacle of full state characterization for entanglement measurement.
- To enable direct and quantitative experimental studies of quantum correlations.
Main Methods:
- Utilizing standard experimental techniques applicable to spin and cold atom systems.
- Employing global measurements, such as neutron scattering cross-sections or cold atom time-of-flight distributions.
- Requiring no prior assumptions about the system's state in the laboratory.
Main Results:
- A lower bound for entanglement can be directly determined from routine global measurements.
- Demonstrated applicability to neutron scattering in solid-state samples.
- Demonstrated applicability to time-of-flight distributions of cold atoms in optical lattices.
Conclusions:
- The proposed scheme successfully quantifies entanglement without full state tomography.
- This method significantly simplifies the experimental study of quantum correlations in many-body systems.
- The approach is versatile and adaptable to various systems and measurement techniques.
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