Study on the decoherence rate of Rydberg polaritons induced by laser frequency fluctuations

Bongjune Kim^1*, Ko-Tang Chen¹, Chia-Yu Hsu¹, Shih-Si Hsiao¹, Yu-Chih Tseng¹, Chin-Yuan Lee¹, Shih-Lun Liang¹, Yi-Hua Lai¹, Ite A. Yu^1,2

¹Physics, National Tsing Hua University, Hsinchu, Taiwan
²Center for Quantum Technology, Hsinchu, Taiwan

* Presenter:Bongjune Kim, email:upfe11@gmail.com

In this presentation, we will report the development of our Rydberg-state EIT system which is aiming to achieve photon-photon interaction or qubit-qubit operation via strong dipole-dipole interaction between Rydberg-state atoms for quantum information manipulation. Unlike the Λ-type EIT configuration under the phase-lock or injection-lock scheme, decoherence rate induced by the frequency fluctuations of the coupling and probe lasers cannot be eliminated in the cascade-type configuration of Rydberg-state EIT. In our experiment, we applied Rydberg-EIT-based locking system with a hot vapor cell [1] to achieve a very low decoherence rate of the system for the generation of Rydberg polaritons. Under the locking method, we investigated our experiment system using slow light Measurement at n = 32 Rydberg state. According to the analytic formula we derived, we estimated the decoherence rate and the corresponding laser frequency fluctuation at various coupling Rabi frequencies.

[1] R. Abel, A. Mohapatra, M. Bason, J. Pritchard K. Weatherill, U Raitzsch, and C. Adams, Applied Physics Letters, 94, 0711107 (2009)

Keywords: Rydberg-state EIT, coherent effect, decoherence rate