QUANTUM PANCAKES FOR QUANTUM ENTANGLEMENT

9988865 Khitrova量子纠缠对于量子中继器至关重要，任何量子信息处理的建议都需要有机会。 这个项目的目标是获得一个足够好的量子煎饼，以实现量子纠缠。 “良好”意味着具有大的偶极矩和辐射主导的寿命和退相干时间。 一个大的偶极矩允许人们用真空场或施加的光脉冲比非辐射退相干时间更快地光学控制煎饼。 基于窄线宽InGaAs/GaAs量子威尔斯的生长和辐射宽度和偶极矩的提取，该提议将采取下一步：通过横向限制这种量子阱的100至200 nm直径部分来制作量子饼。 一个好的煎饼可以用在一个小的三维微腔中，以实现煎饼的过渡和光学模式之间的量子纠缠。该方法将开始与搜索的最佳部分的单量子阱0.8微米的空间分辨率使用传统的光学或0.25微米的分辨率与固体浸没透镜。 将考虑用于横向限制的各种技术，例如，来自生长在量子阱上方的自组织点层的应力，或通过使用紧密聚焦的激光束的局部加热的相互扩散。 候选煎饼将通过多种光学光谱技术进行评估。 差分反射率或吸收将决定积分吸收和偶极矩。 我们将利用兆赫分辨率的连续波非线性光谱和皮秒泵浦-探测测量来研究单光子吸收的影响。 最后，在皮秒共振激发之后的前向或后向发射的条纹相机检测将显示偏振衰减在多大程度上是纯辐射的。

9988865KhitrovaQuantum entanglement is essential for quantum repeaters needed for any of the proposals for quantum information processing to have a chance. The goal of this project is to obtain a quantum pancake that is good enough to achieve quantum entanglement. "Good" means one with a large dipole moment and radiatively dominated lifetime and decoherence time. A large dipole moment allows one to optically control the pancake with the vacuum field or an applied optical pulse faster than nonradiative decoherence times. Based on the growth of narrow-linewidth InGaAs/GaAs quantum wells and extraction of the radiative width and dipole moment, this proposal would take the next step: make a quantum pancake by laterally confining a 100- to 200-nm diameter portion of such a quantum well. A good pancake could be used in a small 3D microcavity to achieve quantum entanglement between a transition of the pancake and the optical mode.The approach will begin with a search for the best portions of a single quantum well with 0.8-micron spatial resolution using conventional optics or 0.25-micron resolution with a solid immersion lens. Various techniques for lateral confinement will be considered, for example, stress from a layer of self-organized dots grown above the quantum well or interdiffusion by local heating using a tightly focused laser beam. Candidate pancakes will be evaluated by a multitude of optical spectroscopic techniques. Differential reflectivity or absorption will determine the integrated absorption and dipole moment. MHz-resolution cw nonlinear spectroscopy and picosecond pump-probe measurements will be used to find out the effect of absorption of a single photon. Finally, streak-camera detection of the forward or backward emission following picosecond resonant excitation will show to what extent the polarization decay is purely radiative.