Free space quantum communication with a portable quantum memory

Abstract

The realization of an elementary quantum network that is intrinsically secure and operates over long distances requires the interconnection of several quantum modules performing different tasks. In this work we report the interconnection of four different quantum modules: (i) a random polarization qubit generator, (ii) a free-space quantum communication channel, (iii) an ultra-low noise portable quantum memory and (iv) a qubit decoder, in a functional elementary quantum network possessing all capabilities needed for quantum information distribution protocols. We create weak coherent pulses at the single photon level encoding polarization states $|H⟩,|V⟩,|D⟩,|A⟩$ in a randomized sequence. The random qubits are sent over a free-space link and coupled into a dual rail room temperature quantum memory and after storage and retrieval are analyzed in a four detector polarization analysis akin to the requirements of the BB84 protocol. We also show ultra-low noise and fully-portable operation, paving the way towards memory assisted all-environment free space quantum cryptographic networks.

8 pages, 6 figures

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Cited by in corpus (6)

• Quantum Communication Using Semiconductor Quantum Dots
• Spacetime effects on wavepackets of coherent light
• Hong-Ou-Mandel interference of polarization qubits stored in independent room-temperature quantum memories
• Proposal for a long-lived quantum memory using matter-wave optics with Bose-Einstein condensates in microgravity
• Characterization of free-space quantum channels
• Entanglement-assisted authenticated BB84 protocol