Coherence generation and population transfer in a three-level ladder system  

作　　者：张冰 姜云 王刚 张理达 吴金辉 高锦岳 

机构地区：[1]College of Physics,Jilin University [2]Key Laboratory of Coherent Light and Atomic and Molecular Spectroscopy of Educational Ministry [3]College of Physics and Electronic Engineering,Mudanjiang Teachers' College [4]Heilongjiang Superhard Materials Key Laboratory

出　　处：《Chinese Physics B》2011年第5期54-60,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant No. 10774059);the National Basic Research Program of China (Grant No. 2006CB921101);the Natural Science Foundation of Heilongjiang Province,China (Grant No. F200928)

摘　　要：This work explores the effect of spontaneous emission on coherence generation and population transfer in a three- level ladder atomic system driven by two pulses in counterintuitive order. With adiabatic evolution and the weak- dephasing approximation, we find that a large coherence and population transfer can be achieved even with spontaneous decay rate. The maximum coherence and population transfer decrease with the increase of spontaneous decay rate from the highest state to intermediate state. But this effect can be compensated by shortening the pulse width and enlarging the delay time. Results show that the coherence generation and population transfer never depend on the spontaneous decay rate from the intermediate state to ground state. The validity of the analytic solution is examined by numerical calculation.This work explores the effect of spontaneous emission on coherence generation and population transfer in a three- level ladder atomic system driven by two pulses in counterintuitive order. With adiabatic evolution and the weak- dephasing approximation, we find that a large coherence and population transfer can be achieved even with spontaneous decay rate. The maximum coherence and population transfer decrease with the increase of spontaneous decay rate from the highest state to intermediate state. But this effect can be compensated by shortening the pulse width and enlarging the delay time. Results show that the coherence generation and population transfer never depend on the spontaneous decay rate from the intermediate state to ground state. The validity of the analytic solution is examined by numerical calculation.

关 键 词：COHERENCE population transfer spontaneous decay 

分 类 号：O562[理学—原子与分子物理] O431.2[理学—物理]