Raman quantum memory with built-in suppression of four-wave-mixing noise

S. E. Thomas, T. M. Hird, J. H.D. Munns, B. Brecht, D. J. Saunders, J. Nunn, I. A. Walmsley, P. M. Ledingham

Research output: Contribution to journalArticlepeer-review

24 Citations (SciVal)


Quantum memories are essential for large-scale quantum information networks. Along with high efficiency, storage lifetime, and optical bandwidth, it is critical that the memory adds negligible noise to the recalled signal. A common source of noise in optical quantum memories is spontaneous four-wave mixing. We develop and implement a technically simple scheme to suppress this noise mechanism by means of quantum interference. Using this scheme with a Raman memory in warm atomic vapor, we demonstrate over an order of magnitude improvement in noise performance. Furthermore we demonstrate a method to quantify the remaining noise contributions and present a route to enable further noise suppression. Our scheme opens the way to quantum demonstrations using a broadband memory, significantly advancing the search for scalable quantum photonic networks.

Original languageEnglish
Article number033801
JournalPhysical Review A
Issue number3
Publication statusPublished - 3 Sept 2019

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics


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