Limits of single-photon storage in a single $Λ$-type atom

Abstract

We theoretically investigate the limits of single-photon storage in a single Λ-type atom, specifically the tradeoff between storage efficiency and storage speed. We show that a control field can accelerate the storage process without degrading efficiency too much. However, the storage speed is ultimately limited by the total decay rate of the involved excited state. For a single-photon pulse propagating in a regular one-dimensional waveguide, the storage efficiency has an upper limit of 50%. Perfect single-photon storage can be achieved by using a chiral waveguide or the Sagnac interferometry. By comparing the storage efficiencies of Fock-state and coherent-state pulses, we reveal the influence of quantum statistics of light on photon storage at the single-photon level. II. MASTER EQUATIONS FOR A Λ-TYPE ATOM DRIVEN BY A QUANTUM PULSERecently, substantial efforts have been devoted to investigating the scattering of propagating quantum pulses by a local quantum system [25,[49][50][51][52]. A systematic master-equation approach has been developed to handle the dynamics the local quantum scatter [53][54][55]. The input-output relation has