Single-Photon-Compatible Telecommunications-Band Quantum Memory in a Hot Atomic Gas
S. E. Thomas, Steven Sagona-Stophel, Zakary Schofield, Ian A. Walmsley, Patrick M. Ledingham
Abstract
Tomorrow's quantum Internet will be powered by light and will work over today's telecommunication infrastructure, so we need low-noise, high-bandwidth, telecom-band quantum optical memory to enable scaling in the presence of loss and quantum operations. The authors have built such a device, using coherent two-photon absorption in warm rubidium vapor. This quantum memory stores gigahertz-bandwidth telecom-band light pulses with mean photon number less than one, and retrieves them with a signal-to-noise ratio exceeding 10${}^{4}$. This makes possible ultrahigh-fidelity storage of single-photon qubits and is compatible with quantum-dot light sources, for hybridized quantum photonic networking.