Quantum Memory and Repeaters: NIST Research
NIST scientists are developing quantum memories and repeaters for long-distance quantum networks. Quantum repeaters are essential for maintaining signal quality over long distances, but they require efficient quantum memories to store and retrieve quantum information.
Two main approaches are being explored:
1. Trapped ions: Can store quantum information for over 30 minutes with low error rates (<10^-3), crucial for repeaters. Current challenge is coupling ions to telecom photons for entanglement distribution over 30 km.
2. Electromagnetically induced transparency (EIT) in cesium ensembles: Can store photons for microseconds, with research focused on cold ensembles for longer storage. Strong pump beam noise is a major challenge.
Key technical points:
- Quantum memories must efficiently couple photonic qubits to storage materials
- Trapped ions offer long storage times and low error rates
- EIT in cesium ensembles provides microsecond storage with ongoing cold ensemble research
- Quantum repeaters require entanglement distribution over long distances
Implementation status:
- Trapped ion quantum memories have demonstrated 30+ minute storage times
- EIT quantum memory has been used for a highly accurate spectrometer
- Current focus is on improving coupling efficiency and reducing errors
Potential impact:
- Enables long-distance quantum communication networks
- Critical for developing practical quantum repeaters
- Could revolutionize quantum internet and secure communication
Implementation timeframes:
- Trapped ion coupling to telecom photons is a remaining challenge
- Cold ensemble EIT research is ongoing
- Overall development is in early stages with proof-of-concept demonstrations
Source: https://www.nist.gov/pml/quantum-networks-nist/technologies-quantum-networks/quantum-memory-and-repeaters
Keywords: entanglement, quantum, repeaters, memory, ions
