Eur. Phys. J. D (2013) 67: 151
https://doi.org/10.1140/epjd/e2013-40024-7

Regular Article

Roles of dephasing in the population transfer in stimulated Raman adiabatic process

¹ Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, and Department of Physics, Hunan Normal University, Changsha 410081, P.R. China
² School of Physics and Electronics, Hunan University of Arts and Science, Changde 415000, P.R. China

^a e-mail: hszeng@hunnu.edu.cn

Received: 12 January 2013
Received in final form: 17 March 2013
Published online: 24 July 2013

Abstract

We investigate the population transfer for a three-level Λ system with both spontaneous emission and dephasing noises via stimulated Raman adiabatic process. Special attention is paid to the dependence of population transfer efficiency on the spontaneous emission rates Γ_1,2 and dephasing rate Γ₃. It is found that the loss of transfer efficiency induced by pure dephasing is much more stronger than that by pure spontaneous emission. Interestingly, the dephasing is not always harmful: modest dephasing can completely or partly reverse the effect of spontaneous emission Γ₂, leading to the efficiency of population transfer from decreasing to increasing with Γ₂.