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.
Dynamical effects of the four-wave mixing enhancement induced by constructive quantum interference 下载免费PDF全文
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.
Highly efficient four-wave mixing induced by quantum constructive interference in rubidium vapour 下载免费PDF全文
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
4.
Highly efficient four-wave mixing induced by quantum constructive interference in rubidium vapour 下载免费PDF全文
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
5.
K. Wiśniewska D. Dziczek Ł. Kłosowski M. Piwiński S. Chwirot 《The European physical journal. Special topics》2007,144(1):167-171
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.
D.V. Kosachiov E.A. Korsunsky 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(3):457-463
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.
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