Quantum optics with thermal atomic vapours.

当代原子物理实验中的许多重要技术都是在热原子蒸气中首次演示的。这些介质非常适合量子光学实验，因为它们结合了联合收割机强的原子-光相互作用，具有长的相干时间，以及充分理解和表征的原子-原子相互作用。在新兴的量子信息和技术领域，有两个潜在的丰富领域使用原子蒸气：作为单光子源，以及作为窄带滤波器以消除不需要的辐射源。本研究项目的主要目标是了解，在量子光学实验的背景下，数值表征和实验测量原子介质的滤波特性。先前在达勒姆的工作表明，增加一个大的磁场大大简化了介质的理论建模。在这项研究中，我们要解决的一个大问题是，在实现实验超窄滤波器时，能级结构的简化是否会导致更高的品质因数。文献中以前的工作往往集中在定性的理解原子-光相互作用的线形;相比之下，在这项工作中，我们的方法的新方面将是使用统计技术来比较我们的理论和数值计算与介质的光学性质，包括热原子蒸气的定量协议。学生将数值计算斯托克斯参数的预期值（即在磁场存在下的原子-光相互作用）为不同的原子细胞，领域和温度;这将是其次是定量理论实验比较;最后建立在获得的理解光学器件的最佳性能应确定和实验验证。

Many of the work-horse techniques of contemporary atomic physics experiments were first demonstrated in hot atomic vapours. These media are ideally suited for quantum-optics experiments as they combine strong atom-light interactions, with long coherence times, and well-understood and characterised atom-atom interaction.In the burgeoning field of quantum information and technology there are two potentially rich areas of using atomic vapours: as sources of single photons, and as narrowband filters to eliminate unwanted source of radiation.The key objectives of this research project are to understand, characterize numerically and measure experimentally the filtering properties of an atomic medium, in the context of quantum optics experiments. Previous work in Durham has shown that adding a large magnetic field dramatically simplifies the theoretical modelling of the medium. One of the big questions we shall address in this investigation is whether the simplification of the energy-level structure leads to higher figures of merit when realising experimental ultranarrow filters. Previous work in the literature has tended to concentrate on the qualitative understanding of the lineshape of the atom-light interaction; by contrast, in this work, the novel aspect of our methodology will be to use statistical techniques to compare the quantitative agreement of our theoretical and numerical calculations with the optical properties of the medium comprising a thermal atomic vapour. The student will calculate numerically the expected values of the Stokes parameters (that characterise atom-light interactions in the presence of a magnetic field) for different atomic cells, fields and temperatures; this shall be followed by quantitative theory-experiment comparisons; finally building on the understanding gained the optimal properties of optical devices shall be ascertained and verified experimentally.