Macroscopic Quantum Tunneling in Ultracold Quantum Gases

穿越势垒是量子力学最基本、最非凡的特征之一。它在隧道二极管和超导量子干涉器件（squid）等重要技术中发挥着关键作用，这两种技术都用于从电子到生物测量的常见设备。原子、分子和光学理论在桌面实验中探索物理学中的基本问题有着悠久的历史，从研究宇宙基本对称性的粒子物理标准模型的极限到冷分子中基本物理常数的时间变化。我们将在超冷量子气体的实际实现中，推动量子力学的极限和宏观的不同概念。我们专注于宏观量子隧穿（MQT），即许多粒子同时隧穿，其中许多突出的问题仍未得到解答。玻色-爱因斯坦凝聚体和超冷量子气体为探索MQT提供了理想的环境，因为它们是高度可调和可控的宏观量子系统，其中的理论思想可以直接在当前的实验中实现。我们采取多方面的方法来实现更广泛的影响目标。首先，我们将继续组织国内和国际研讨会和会议，包括最近在2013年春季举办的冷分子项目。其次，我们将通过科罗拉多矿业学院（CSM）的高级设计/高级论文项目，CSM的学士/硕士联合项目，以及NSF本科生研究经验项目，与大量本科生研究人员合作。第三，我们将继续在我们的研究小组内营造一个包容的、多样化的环境，以支持物理学中代表性不足的群体。最后，从太空计划到全球气候变化，对学生进行严格的数值技术和高性能并行计算方面的培训是在社会许多领域取得成功的关键。我们将培养这样的学生，并支持从本科到博士后阶段参与这项工作的PI。

Tunneling through a potential barrier is one of the most basic and extraordinary features of quantum mechanics. It plays a key role in important technologies such as tunneling diodes and superconducting quantum interference devices (SQUIDs), both used in common devices ranging from electronics to biological measurements. Atomic, molecular, and optical theory has a long history of exploring fundamental questions in physics in tabletop experiments, from limits on the standard model of particle physics in studies of basic symmetries of the universe to time variation of fundamental physical constants in cold molecules. We will push the limits of quantum mechanics and disparate notions of what is macroscopic, in practical realizations in ultracold quantum gases. We focus on macroscopic quantum tunneling (MQT), i.e., tunneling of many particles at once, where very many outstanding problems remain unanswered. Bose-Einstein condensates and ultracold quantum gases provide an ideal context in which to explore MQT because they are highly tunable and controllable macroscopic quantum systems in which theoretical ideas can be realized directly in present experiments.We have a multi-faceted approach to meet broader impact goals. First, we will continue to organize national and international workshops and conferences including the recent cold molecules program in Spring 2013. Second, we will work with large numbers of undergraduate researchers via the Colorado School of Mines' (CSM) senior design / senior thesis program, CSM's combined BS/MS programs, and the NSF Research Experience for Undergraduates program. Third, we will continue to foster an accepting, diverse environment within our research group to support underrepresented groups in physics. Finally, the training of students in rigorous numerical techniques and high-performance parallel computing is key to success in a number of arenas in society, from the space program to global climate change. We will train such students, and support a PI involved in that effort from the undergraduate through post-doctoral levels.