CAJ | 학술논문

量子相干控制前沿问题及应用研究是本世纪物理学前沿领域的重要研究内容.而基于暗态的量子相干控制技术已经导致了在相干布居捕获、绝热跟随、量子信息等多方面的应用.论文主要进行双暗态原子系统动力学行为的若干量子相干控制研究,包括双暗态四能级原子系统的绝热跟随特性研究,双暗态作用提高克尔非线性的新方案提出,自发辐射诱导相干实现非线性极化率的提高以及双通道高效四波混频过程的实现等.
양자상간공제전연문제급응용연구시본세기물이학전연영역적중요연구내용.이기우암태적양자상간공제기술이경도치료재상간포거포획、절열근수、양자신식등다방면적응용.논문주요진행쌍암태원자계통동역학행위적약간양자상간공제연구,포괄쌍암태사능급원자계통적절열근수특성연구,쌍암태작용제고극이비선성적신방안제출,자발복사유도상간실현비선성겁화솔적제고이급쌍통도고효사파혼빈과정적실현등.
In this thesis, quantum coherent control of dynamic properties of double-dark-resonance atomic systems is pursued in detail. First we show our scheme for creating atomic coherent superposition states via the technique of stimulated Raman adiabatic passage in a Lambda-type four-level system. With the application of a control field, it is found that the presence of double dark states leads to two arbitrary coherent superposition states with equal amplitude but inverse relative phases, even though the condition of multiphoton resonance is not met. The suitable manipulation of the control field and detunings enables the proposed scheme to create any coherent superposition states one desired. Then, in the above mentioned double-dark-resonant system, a scheme for giant enhancement of the Kerr nonlinearity is put forward. Compared with that generated in a single-dark-resonance system, the Kerr nonlinearity can be enhanced by several orders of magnitude with vanishing linear absorption. We attribute this dramatic enhancement to the interaction of dark resonances. As another possible means for enhancement of Kerr nonlinearity, spontaneously generated coherence is proposed. Meanwhile, a theoretical investigation is carried out in a five-level tripod system for obtaining a high efficiency double-channel four-wave-mixing process. By manipulating the intensity of the two coupling fields, the conversion efficiency of four-wavemixing can be controlled.