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A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Quantum Storage of Three-Dimensional Orbital-Angular-Momentum Entanglement in a Crystal
Zong-Quan Zhou1, Yi-Lin Hua1, Xiao Liu1
1Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026, China and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China.
Researchers demonstrate quantum storage of high-dimensional orbital-angular-momentum entanglement in rare-earth crystals. This breakthrough in solid-state quantum memory is crucial for developing advanced quantum repeaters and photonic information processing.
Area of Science:
- Quantum Information Science
- Quantum Optics
- Solid-State Physics
Background:
- Quantum entanglement, a fundamental resource in quantum information science, requires robust storage mechanisms for practical applications.
- Orbital angular momentum (OAM) offers a high-dimensional encoding capability for photonic qubits, but its stable storage remains challenging.
Purpose of the Study:
- To demonstrate the quantum storage of three-dimensional (3D) orbital-angular-momentum (OAM) photonic entanglement.
- To verify the integrity of the stored entanglement and the storage process using quantum correlations and process tomography.
- To assess the reliability and capacity of the quantum memory for multi-spatial-mode storage.
Main Methods:
- Utilized rare-earth-ion-doped crystals as the solid-state medium for quantum memory.
- Stored 3D OAM photonic entanglement and subsequently retrieved it.
- Confirmed entanglement preservation by violating a generalized Bell-type inequality after storage.
- Quantified storage fidelity using complete quantum process tomography in 3D.
- Evaluated the memory's capacity for multiple spatial modes (up to 51).
Main Results:
- Successfully stored 3D OAM photonic entanglement in a rare-earth-ion-doped crystal.
- Demonstrated high fidelity (0.993±0.002) for the quantum memory process.
- Confirmed the preservation of entanglement through a significant violation of the generalized Bell-type inequality (S=2.152±0.033).
- Showcased high reliability for storing weak coherent pulses across 51 spatial modes.
Conclusions:
- Rare-earth-based solid-state devices can reliably store high-dimensional photonic entanglement.
- This technology is a significant step towards building high-dimensional and multiplexed quantum repeaters.
- The multimode capacity of these optical processors extends beyond temporal and spectral degrees of freedom, offering new possibilities for photonic information processing.
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