Telecom-Wavelength Atomic Quantum Memory in Optical Fiber for Heralded Polarization Qubits.

Area of Science:

• Quantum Information Science
• Photonics
• Atomic Physics

Background:

• Polarization-encoded photons at telecommunication wavelengths are crucial for photonic quantum information technologies.
• Existing fiber-optic infrastructure enables long-distance quantum qubit distribution.
• A compatible optical quantum memory is essential for building these technologies.

Purpose of the Study:

• To experimentally demonstrate an atomic quantum memory for telecom-wavelength photons.
• To enable reversible mapping of quantum states encoded in photon polarization.
• To develop a building block for practical photonic quantum information processing.

Main Methods:

• Utilized the atomic frequency comb protocol.
• Employed an ensemble of erbium atoms doped into an optical fiber.
• Stored and retrieved heralded polarization qubits at a telecom wavelength.

Main Results:

• Achieved near-unity fidelity for storing and retrieving polarization qubits.
• Demonstrated the first atomic quantum memory for direct polarization qubit mapping at telecom wavelengths.
• Showcased a broadband light-matter interface.

Conclusions:

• The developed atomic quantum memory shows potential for future quantum information processing.
• Overcame limitations in storage efficiency and time in this proof-of-principle demonstration.
• This work paves the way for integrated quantum memories in fiber-optic systems.