Theory of noise suppression in Λ-type quantum memories by means of a cavity

Quantum memories, capable of storing single photons or other quantum states of light, to be retrieved on demand, offer a route to large-scale quantum information processing with light. A promising class of memories is based on far-off-resonant Raman absorption in ensembles of Λ-type atoms. However,...

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Bibliographic Details
Main Authors: Nunn, JAS, Munns, JHD, Thomas, SE, Kaczmarek, KT, Qiu, C, Feizpour, A, Poem, E, Brecht, B, Saunders, DJ, Ledingham, PM, Reddy, DV, Raymer, MG, Walmsley, IA
Format: Journal article
Published: American Physical Society 2018
Description
Summary:Quantum memories, capable of storing single photons or other quantum states of light, to be retrieved on demand, offer a route to large-scale quantum information processing with light. A promising class of memories is based on far-off-resonant Raman absorption in ensembles of Λ-type atoms. However, at room temperature these systems exhibit unwanted four-wave mixing, which is prohibitive for applications at the single-photon level. Here, we show how this noise can be suppressed by placing the storage medium inside a moderate-finesse optical cavity, thereby removing the main roadblock hindering this approach to quantum memory.