首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到10条相似文献,搜索用时 46 毫秒
1.
We study the control of quantum interference in a four-level atom driven by three coherent fields forming a closed loop. The spontaneous emission spectrum shows two sets of peaks which are dramatically influenced by the fields. Due to destructive quantum interference, a dark line can be observed in the emission spectrum, and the condition of the dark line is given. We found that the conversion between destructive and constructive quantum interference can be achieved through controlling the Rabi frequency of the external fields.  相似文献   

2.
薛艳  王刚  吴金辉  张冰  高锦岳 《中国物理 B》2011,20(3):33403-033403
In a four-level system of ultracold 87Rb atoms, through analytical and numerical calculations we propose an efficient scheme to achieve the enhanced four-wave mixing process and demonstrate its dynamical control by various parameters such as the travel distance z, probe detuning $\delta$ and the probe pulse width $\tau$. In particular, we find that the maximal intensity of the nonlinearly generated signal pulse can be about 80% of the initial input probe under the optimal condition. This greatly enhanced conversion efficiency occurs due to the constructive quantum interference between two different components of the generated signal pulse.  相似文献   

3.
王刚  薛艳  崔淬砺  曲艺  高锦岳 《中国物理 B》2012,21(3):34205-034205
We demonstrate efficient four-wave mixing with an intensity conversion efficiency of nearly 100% in theory without considering the Doppler-broadening effect in a four-level double-Λ system of hot 87Rb gas. The corresponding experimental value of about 73% was reported in our earlier work under the same conditions. This dramatic efficiency is critically dependent on the constructive interference between two four-wave mixing processes relevant to the internally generated four-wave mixing signal.  相似文献   

4.
We demonstrate efficient four-wave mixing with an intensity conversion efficiency of nearly 100% in theory without considering the Doppler-broadening effect in a four-level double-Λ system of hot 87 Rb gas.The corresponding experimental value of about 73% was reported in our earlier work under the same conditions.This dramatic efficiency is critically dependent on the constructive interference between two four-wave mixing processes relevant to the internally generated four-wave mixing signal.  相似文献   

5.
Yang and collaborators reported recently observation of unexpected resonaces in so-called hybrid excitation spectra of sodium vapour. Yang and Xie presented a theoretical model in which the resonances were interpreted as in terms of collision constructive quantum interference effects. This work reports results of testing of the applicability range of the model and demonstrates its serious limitations.  相似文献   

6.
7.
Frequency conversion process is studied in a medium of atoms with a configuration of levels, where transition between two lower states is driven by a microwave field. In this system, conversion efficiency can be very high by virtue of the effect of electromagnetically induced transparency (EIT). Depending on intensity of the microwave field, two regimes of EIT are realized: “dark-state” EIT for the weak field, and Autler-Townes-type EIT for the strong one. We study both cases via analytical and numerical solution and find optimum conditions for the conversion. Received 13 December 1999 and Received in final form 6 March 2000  相似文献   

8.
白云飞  翟淑琴  郜江瑞  张俊香 《中国物理 B》2011,20(3):34207-034207
In this paper,the frequency conversion of quantum states based on the intracavity nonlinear interaction is proposed.The fidelity of an input state after frequency conversion is calculated,and it is shown the noise-free frequency conversion of a quantum state can be achieved by injecting a strong signal field.The dependences of conversion efficiency on the pump parameter,extra losses and input state amplitude are also analysed.  相似文献   

9.
We show that inducing modulation instability with a weak modulation whose frequency is such that its second harmonic falls within the band of instability may lead to asynchronous Fermi-Pasta-Ulam recurrence and efficient transfer of power from the pump into the second harmonic of the modulation, resulting in a periodic modulation at the second harmonic with extinction ratios in excess of 30 dB.  相似文献   

10.
We propose a scheme for efficient optical frequency conversion at the single-photon power level. The scheme exploits the quantum interference of single-photon states at a three-level quantum emitter coupled to a Sagnac interferometer. We show that this device can achieve single-photon frequency up- or down-conversion with near unity efficiency.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号