Transitions, dynamics, and spin squeezing in a ferromagnetic spinor condensate

实验研究计划继续实验研究一种新型原子气体的集体行为：Rb-87的旋量玻色-爱因斯坦凝聚体（BEC）。 这项工作是在凝聚态物理和超冷原子物理之间的交叉。 这个“交叉”区域是研究远离平衡的强相关系统的一个有益领域。 超冷原子的环境提供了一个特殊的工具来研究动力学，与困扰传统固体或液体系统的耗散热环境的耦合最小。该项目的总主题是研究热或量子涨落在确定过渡动力学性质方面的作用。 特别令人感兴趣的是量子相变的动力学，在量子相变中，相关性激增，控制系统的行为，并迅速改变其特性。这项研究将揭示旋量气体的热性质。特别是，该项目将表征量子相变时的量子动力学和拓扑缺陷形成，量子相变与标度行为和临界指数定量相关，直接观察二维玻色气体中的自旋涡旋，其中涡旋/反涡旋生成和配对的Berezinskiii-Kosterlitz-BKT（BKT）机制应该发生，并在旋量BEC中实现空间分辨的自旋压缩。这项工作的更广泛影响之一是使用开发的磁化敏感成像技术，对小区域的磁场进行精确测量，这可能具有科学和技术应用。 此外，本科生，研究生和博士后研究员将接受超冷原子研究的培训。 该计划还包括一个组成部分，通过为本科教学实验室开发实验，将现代超冷原子物理学的发展扩展到本科教育。

The experimental research program continues experiments examining the collective behavior of a novel atomic gas: a spinor Bose-Einstein condensate (BEC) of Rb-87. This work is at the crossover between condensed-matter physics and ultracold atomic physics. This "crossover" region is a rewarding area to study strongly correlated systems that are far from equilibrium. The environment of ultracold atoms provides an exceptional tool to study dynamics with minimal coupling to a dissipative thermal environment that plagues conventional solid or liquid systems. The general theme of the project is to study the role of thermal or quantum fluctuations in determining the nature of the dynamics at the transitions. Of particular interest are the dynamics at quantum phase transitions, at which correlations proliferate, dominate the behavior of the system, and rapidly change its character. The research will shed light on the thermal properties of spinor gases. In particular, the project will characterize quantum dynamics and topological defect formation at a quantum phase transition which connects quantitatively to scaling behavior and critical exponents, directly observe spin vortices in a two-dimensional Bose gas in which the Berezinskii-Kosterlitz-Thouless (BKT) mechanism of vortex/antivortex generation and pairing should occur, and achieve spatially-resolved spin squeezing in a spinor BEC. One of the broader impacts of this work is to use the magnetization-sensitive imaging technique developed to make precision measurements of magnetic fields over small areas, which could have both scientific and technological applications. Further, undergraduates, graduate students, and postdoctoral fellows will be trained in ultracold atom research. The program also includes a component extending developments from modern ultracold atomic physics to undergraduate education by developing experiments for undergraduate teaching laboratories.