We present an improved version of the superatom(SA)model to examine the slow-light dynamics of a few-photons signal field in cold Rydberg atoms with van der Waals(vdW)interactions.A main feature of this version is tha...We present an improved version of the superatom(SA)model to examine the slow-light dynamics of a few-photons signal field in cold Rydberg atoms with van der Waals(vdW)interactions.A main feature of this version is that it promises consistent estimations on total Rydberg excitations based on dynamic equations of SAs or atoms.We consider two specific cases in which the incident signal field contains more photons with a smaller detuning or less photons with a larger detuning so as to realize the single-photon-level light storage.It is found that vdW interactions play a significant role even for the slow-light dynamics of a single-photon signal field as distributed Rydberg excitations are inevitable in the picture of dark-state polariton.Moreover,the stored(retrieved)signal field exhibits a clearly asymmetric(more symmetric)profile because its leading and trailing edges undergo different(identical)traveling journeys,and higher storage/retrieval efficiencies with well preserved profiles apply only to weaker and well detuned signal fields.These findings are crucial to understand the nontrivial interplay of single-photon-level light storage and distributed Rydberg excitations.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11534002 and 12074061)the Cooperative Program by the Italian Ministry of Foreign Affairs and International Cooperation(No.PGR00960)the National Natural Science Foundation of China(No.11861131001).
文摘We present an improved version of the superatom(SA)model to examine the slow-light dynamics of a few-photons signal field in cold Rydberg atoms with van der Waals(vdW)interactions.A main feature of this version is that it promises consistent estimations on total Rydberg excitations based on dynamic equations of SAs or atoms.We consider two specific cases in which the incident signal field contains more photons with a smaller detuning or less photons with a larger detuning so as to realize the single-photon-level light storage.It is found that vdW interactions play a significant role even for the slow-light dynamics of a single-photon signal field as distributed Rydberg excitations are inevitable in the picture of dark-state polariton.Moreover,the stored(retrieved)signal field exhibits a clearly asymmetric(more symmetric)profile because its leading and trailing edges undergo different(identical)traveling journeys,and higher storage/retrieval efficiencies with well preserved profiles apply only to weaker and well detuned signal fields.These findings are crucial to understand the nontrivial interplay of single-photon-level light storage and distributed Rydberg excitations.