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Measuring entanglement entropy in a quantum many-body system.
Rajibul Islam1, Ruichao Ma1, Philipp M Preiss1
1Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Nature
|December 4, 2015
Summary
Researchers measured spatial entanglement in itinerant particles using quantum interference. This breakthrough allows direct measurement of quantum purity and entanglement entropy in complex many-body systems.
Area of Science:
- Quantum mechanics
- Quantum information sciences
- Condensed matter physics
Background:
- Entanglement, a key quantum phenomenon, describes non-local correlations.
- Measuring entanglement is challenging, particularly in systems of interacting delocalized particles.
- Direct experimental measurement of spatial entanglement in such systems has been elusive.
Purpose of the Study:
- To develop a method for measuring spatial entanglement in systems of itinerant particles.
- To enable direct experimental measurement of entanglement properties in strongly correlated many-body systems.
- To utilize entanglement measurements for characterizing quantum phases and dynamics.
Main Methods:
- Utilized quantum interference of "many-body twins" to measure entanglement.
- Employed single-site-resolved control of ultracold bosonic atoms in optical lattices.
- Prepared and interfered two identical copies of a many-body state.
Main Results:
- Successfully measured quantum purity, Rényi entanglement entropy, and mutual information.
- Demonstrated a novel experimental approach for quantifying spatial entanglement.
- Provided a new tool for studying quantum correlations in complex systems.
Conclusions:
- The developed method enables direct measurement of entanglement in challenging many-body systems.
- This technique paves the way for characterizing quantum phases and dynamics using entanglement.
- Advances the field of quantum information sciences and condensed matter physics.
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