Few-photon storage on a second timescale by electromagnetically induced transparency in a doped solid

Abstract

We present the experimental demonstration of light storage towards the single photon level at a long storage time by electromagnetically induced transparency in a rare-earth ion-doped Pr3+:Y2SiO5 crystal. We apply decoherence control by static magnetic fields and appropriately designed radio-frequency composite pulse sequences to prolong the storage time in the memory. A rare-earth ion-doped filter crystal prepared by optical pumping serves to efficiently separate the signal at the single photon level from optical noise. Multipass setups around the memory and the filter crystal improve the storage efficiency and filter selectivity. Already without decoherence control, the setup permits storage of single photons in the microsecond regime at a storage efficiency of 42%. With decoherence control we demonstrate storage of weak coherent pulses containing some 10 photons for up to 10 s at a storage efficiency of several percent. The experimental data clearly demonstrate the applicability of EIT light storage to implement a true quantum memory in Pr3+:Y2SiO5 at long storage times. The scientific findings and technical developments are of relevance also to other protocols and media for quantum information storage.

Quantum State Storage in a Travelling Dark State Polariton, under a Standing Wave Control Laser Field in a Solid-State Medium

“…We have also proposed an experiment for realising the standing wave control laser field EIT system and subsequent probe pulse storage in a rare earth metal doped YSO crystal, cryogenically cooled to 4.5 K. Although stationary pulses have been stored and studied in a warm and cold atomic gaseous [9] [14], the case of travelling probe pulse under the effect of counterpropagating control laser field, which we have proposed to study experimentally, has not been done in a solid-state medium. Most recently, a travelling photon pulse, under the application of travelling control laser field, has been stored for up to 100 seconds in the levels 3 H4 ↔ 1 D2 of Pr 3+ : Y2SiO5 by M. Hain et al (2022). [18] We have proposed the experiment to be performed on the same medium and have predicted by our analysis, that a greater coherence time for the storage of the pulse should be observed in this process.…”

“…Most recently, a travelling photon pulse, under the application of travelling control laser field, has been stored for up to 100 seconds in the levels 3 H4 ↔ 1 D2 of Pr 3+ : Y2SiO5 by M. Hain et al (2022). [18] We have proposed the experiment to be performed on the same medium and have predicted by our analysis, that a greater coherence time for the storage of the pulse should be observed in this process. The storage time is, however, limited because of the unavoidable spontaneous emissions.…”

What are the ultimate limits of photonic quantum memories?

“…Photonic quantum memories are required in many applications in quantum information science with varying performance requirements depending on specific applications. Although classical light storage has been demonstrated in time scales of minutes (Dudin and Kuzmich, 2013;Heinze et al, 2013) to hours (Ma et al, 2021) in different systems, storing true single photons and single photon level coherent pulses are still limited to around a few seconds at most (Wang et al 2021;Ortu et al, 2022;Hain et al, 2022;Stas et al 2022). In this question we would like to explore what the challenges for quantum memory storage for the purposes of quantum communication and the distribution of entanglement are, e.g.…”

Performance and application analysis of quantum memory

“…步提升存储效率 [36−40] . 2013年, 瑞典隆德大学Rippe 研究组 [39,41] 采用强增强原子频率梳技术提升了光 存储效率, 存储效率达到56%. 2016年, 德国达姆 施塔特工业大学Halfmann研究组 [40] 设计了一种 多次穿过的方案, 利用 晶体实现了 76%的高效率光存储.…”