Many-Body Echo, Topological Defects and Long-Range Interactions in Dressed Bose-Einstein Condensates

该研究计划试图探索量子物理学中一些最有趣甚至违反直觉的预测：（1）量子力学描述的复杂系统的演化是可逆的，（2）具有奇异性质的粒子可以从激发的量子场中出现，（3）遥远物体之间的相互作用和纠缠可以通过真空中的虚拟激发来介导。由于复杂量子系统的动力学通常难以被经典计算机处理，该项目采用了三组实验，使用超冷原子和分子作为模拟平台来测试预测，这一灵感最初来自物理学家理查德·费曼。在这里，超冷的原子和分子可以被精确地编程，以重现可以测试预测的条件。对这些现象的深入理解将拓宽我们对量子世界中基本定律和奇异现象起源的理解。 该计划还体现了一个教育组成部分，通过S.M.A.R.T.与URM高中学生分享科学发现的兴奋。计划和本科生谁将领导和执行悬浮科学的本科研究中心的独立研究。具体来说，对于第一个目标，测试可逆性，一些“多体回波”计划将被开发，以扭转加热的相互作用的原子时，他们耦合到一个随时间变化的电磁场。这种加热是通用的，并且对许多量子材料和量子气体实验是有害的。在这样的系统中，一个新发现的对称性表明系统的方法来撤销加热，类似于自旋回波序列，在NMR实验中重新相位。第二个目标是研究耦合到合成规范场的量子气体中的拓扑缺陷。在这里，规范场是由势能和原子相互作用的调制合成的，并且缺陷自发形成。一个完整的表征的缺陷将实现其动态响应的合成领域的系统调查。第三个尝试是将玻色子铯原子浸入简并费米气体中，这有望诱导玻色子之间的长程相互作用和纠缠。高分辨率成像和光学投影将被用来测试和量化玻色子的相关性，其长度尺度大于直接相互作用的范围。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

This research program attempts to explore some of the most intriguing and even counterintuitive predictions in quantum physics: (1) evolution of complex systems described by quantum mechanics is reversible, (2) particles with exotic properties can emerge from an excited quantum field, and (3) interactions and entanglement between distant objects can be mediated by virtual excitations in vacuum. As dynamics of complex quantum systems are frequently intractable by classical computers, this project employs three sets of experiments using ultracold atoms and molecules as a simulation platform to test the predictions, an inspiration originally from physicist Richard Feynman. Here the ultracold atoms and molecules can be precisely programmed to reproduce the conditions under which the predictions can be tested. A deeper understanding of these phenomena will broaden our understanding of the fundamental laws and the origin of exotic phenomena in the quantum world. The program also embodies an education component that shares the excitement of discoveries in science with URM high school students through the S.M.A.R.T. program and with undergraduate students who will lead and perform independent research in the Undergraduate Research Center of Levitation Science. Specifically, for the first objective, to test reversibility, a number of “many-body echo” schemes will be developed to reverse the heating of interacting atoms when they are coupled to a time-dependent electromagnetic field. Such heating is generic and detrimental to many quantum material and quantum gas experiments. In such systems, a newly identified symmetry suggests systematic approaches to undo the heating, analogous to spin echo sequences that rephase in NMR experiments. The second objective is to investigate topological defects in a quantum gas coupled to a synthetic gauge field. Here the gauge field is synthesized by modulations of the potential energy and atomic interactions, and the defects form spontaneously. A full characterization of the defects will be realized by a systematic investigation of their dynamical response to the synthetic fields. The third effort involves bosonic cesium atoms immersed in a degenerate Fermi gas, which is expected to induce long-range interactions and entanglement between the bosons. A high-resolution imaging and optical projection will be employed to test and quantify the correlations of bosons at length scales greater than the range of direct interactions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.