Ladder-type Optical Quantum Memory from the Doppler-broadened Atomic Ensemble*

Quantum technology is one of the most important fields including quantum communication, quantum computing, and quantum sensing. Quantum memory plays a pivotal role in enabling practical quantum technologies. Recently, optical quantum memory based on Doppler-broadened atomic ensembles in a ladder-type energy configuration has emerged as a topic of considerable interest due to its fast, low-noise operation and large bandwidth, which is compatible with various single-photon sources [1,2].

In this work, we store and retrieve a heralded single photon of 780 nm and develop the experimental setup for arbitrary polarization state memory from our telecom biphoton source [3]. In our experiment, we used the photon pair generation from the ⁸⁷Rb atom for the 5S_1/2–5P_3/2 transition at 780.2 nm and the 5P_3/2–4D_5/2 transition at a telecom wavelength of 1529.4 nm. We utilize the EIT-based optical quantum memory in the 5S_1/2 (F=2)-5P_3/2 (F’=3)-5D_5/2 (F’’=4) transition of ⁸⁷Rb atom. We believe our result provides practical pathways for implementing quantum nodes for implementing quantum nodes for efficient transportation of quantum photonic states.

Reference

[1] Ran Finkelstein, Eilon Poem, Ohad Michel, Ohr Lahad and Ofer Firstenberg ”Fast, noise-free memory for photon synchronization at room temperature.” Sci. Adv. 4, eaap8598 (2018)

[2] Benjamin Maaß, Norman Vincenz Ewald, Avijit Barua, Stephan Reitzenstein and Janik Wolters “Room-temperature ladder-type optical memory compatible with single photons from semiconductor quantum dots” Phys. Rev. Applied 22, 044050 (2024)

[3] Hansol Jeong, Heewoo Kim and Han Seb Moon, “High-Performance Telecom-Wavelength Biphoton Source from a Hot Atomic Vapor Cell.” Adv Quantum Technol.  7, 2300108 (2024)