Quantum Coherences, Fluctuations and Chaos

*9800966 Sundaram在经典动力学的宏观世界中，混沌指的是对初始条件的极端敏感。当混沌占主导地位时，就会产生重要的后果，比如所有不同解决方案的可能性相等。这些反过来又重新审视了我们对自然界统计理论长期行为的理解中的许多悬而未决的问题。即使是这种简单的混沌观点，也不能很好地延续到微观或量子世界，因为微观世界或量子世界由波动效应主导。干涉和绕射效应抑制了经典的对初始条件的敏感性，并导致了更好的构型。这些效应统称为量子混沌，包括即使在经典描述中也存在非一致性这一特征，这些效应会成倍增加。一般来说，混沌和规则或稳定区域共存，这种“混合空间”动力学的量子后果很少被理解。这一机制也与最近在各种新奇背景下进行的一系列不同寻常的实验有关。拟议的研究继续进行关于混合空间量子相干的表征以及对其对环境噪声的稳健性的详细分析的工作。数值和解析相结合的方法特别针对原子光学，作为研究结果的实验试验台。预计这些发现将有助于澄清经典描述和量子描述可以协调的条件。

***9800966Sundaram In the macroscopic world of classical dynamics, chaos refers to an extreme sensitivity to the starting or initial condition. When chaos is dominant important consequences, such as the equal likelihood of all distinct solutions, result. These, in turn, revisit many unanswered questions in our understanding of the long-time behavior of statistical theories of nature. Even this simple view of chaos does not carry over well to the microscopic or quantum world, which is dominated by wave effects. Interference and diffraction effects suppress the classical sensitivity to initial conditions and result in preferred configurations. Collectively referred to as quantum chaos, these effects multiply on including the feature that non-uniformities exist even in the classical description. In general, chaotic and regular or stable regions coexist and the quantum consequences of this `mixed space' dynamics are poorly understood. This regime is also pertinent to a recent, and unusual, confluence of experiments in a variety of novel contexts. The proposed study continues with ongoing work on the characterization of the mixed space quantum coherences as well as a detailed analysis of their robustness to environmental noise. The combination numerical and analytic method specifically targets atom optics as the experimental test bed for the findings. It is anticipated that the findings will help clarify the conditions under which the classical and quantum descriptions can be reconciled.***