Measurement-induced, spatially-extended entanglement in a hot, strongly-interacting atomic system
Jia Kong1,2, Ricardo Jiménez-Martínez3, Charikleia Troullinou3
1Department of Physics, Hangzhou Dianzi University, 310018, Hangzhou, China. jia.kong@hdu.edu.cn.
Nature Communications
|May 17, 2020
Summary
Promoting random interactions, not just isolation, can create and maintain quantum entanglement in hot atomic vapors. This breakthrough enables complex entangled states for advanced quantum sensing beyond classical limits.
Area of Science:
- Quantum Physics
- Atomic Physics
- Quantum Information Science
Background:
- Quantum technologies rely on entanglement but typically require extreme cold and isolation to prevent decoherence.
- Protecting quantum states from environmental interactions is a major challenge in quantum technology development.
Purpose of the Study:
- To investigate if promoting random interactions, rather than isolation, can generate and preserve entanglement in a quantum system.
- To explore the potential of hot, strongly-interacting atomic systems for quantum entanglement and sensing.
Main Methods:
- Utilized optical quantum non-demolition measurement to induce entanglement in a hot alkali vapor.
- Employed Bayesian statistics and spin-squeezing inequalities to quantify entanglement.
- Characterized entanglement in a regime dominated by spin-exchange collisions.
Main Results:
- Successfully generated and preserved entanglement in a hot atomic vapor with strong random interactions.
- Demonstrated that a significant fraction of atoms (1.52(4)×1013 out of 5.32(12)×1013) entered singlet-type entangled states.
- Showed that these entangled states persisted for extended periods (tens of spin-thermalization times) and spanned large distances.
Conclusions:
- High temperatures and strong random interactions do not necessarily destroy many-body quantum coherence.
- Collective quantum measurements can create highly complex entangled states in hot atomic systems.
- Hot, strongly-interacting atomic media are suitable for quantum sensing applications exceeding the standard quantum limit.
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