Search for Universality in the Dynamics of Strongly Correlated Ultracold Fermions

我们周围的世界在不断变化。在这些动态中，可能会出现均衡秩序。但是，我们认定为生命本身的日常动态不可能在平衡中存在，因为(例如)离子浓度的梯度驱动神经的动作电位。在早期宇宙的宇宙学中，在经济市场动力学中，在重离子碰撞中的夸克-胶子等离子体中，在超导体的电阻率中，非平衡动力学被研究得多种多样。我提议用研究动力学的超冷原子做实验。当冷却到纳米开尔文状态时，中性钾的费米子同位素可以模拟电子在固体中的行为，甚至可以探索固体材料无法实现的场景。在任何一种情况下，我们使用冷原子的“量子模拟”方法的优势是前所未有的调整和表征样本的能力。这使得我们探索的模型没有留下任何不确定性的余地，因此观察到的任何现象或行为都是对我们对多体物理理解的明确测试。拟议的研究计划将涉及三个具体的研究目标。第一系列实验调谐量子线中的主波相互作用，并测量粒子-粒子关联。我们能找到一维玻色系统和费米系统之间预测的二元性的证据吗？第二系列实验测量了完美晶体中强相互作用费米子的导电性。电阻率有普遍的极限吗？第三系列实验将尝试使用轨道自由度来设计新的量子态。这项研究的长期目标是阐明粒子间的相互作用如何限制弛豫过程，产生磁性，并使新的量子态成为可能。拟议的实验具有挑战性，但潜在的好处是巨大的。我们的研究结果将直接洞察聚合模型的不可解动力学。拟议的工作将为年轻的科学家和工程师提供有益的研究经验。本科生、研究生和博士后研究员将获得激光、数字和模拟电子、计算机编程和控制集成、真空技术、微波设计、建立数学模型和机械车间技能的经验。这些高素质人员的职业发展还包括在研究小组中担任领导角色，参加国际会议并在国际会议上发表演讲，以及参与公共教育、旅游和讲座。

The world around us is constantly changing. Out of these dynamics, equilibrium order can emerge. But the everyday dynamics we identify as life itself cannot exist in equilibrium, because (for instance) gradients in ion concentrations drive action potentials in nerves. Non-equilibrium dynamics are studied diversely, in cosmology of the early Universe, in economic market dynamics, in quark-gluon plasma in heavy-ion collisions, and in the resistivity of superconductors. I propose experiments with ultracold atoms that study dynamics. When cooled to the nanokelvin regime, the fermionic isotope of neutral potassium can emulate the behaviour of electrons in solids, or even explore scenarios inaccessible with solid materials. In either case, the advantage of our "quantum simulation" approach using cold atoms is an unprecedented ability to tune and characterize the sample. This leaves no room for uncertainty about the model we explore, so that any phenomena or behaviour observed is a clear test of our understanding of many-body physics. The proposed research program will address three specific research objectives. A first series of experiments tunes principal-wave interactions in a quantum wire and measures particle-particle correlations. Can we find evidence of predicted duality between one-dimensional Bose and Fermi systems? A second series of experiments measures the conductivity of strongly interacting fermions in a perfect crystal. Is there a universal limit of resistivity? A third series of experiments will attempt to use the orbital degree of freedom to engineer new quantum states. The long-term goal of this research is to elucidate how inter-particle interactions limit relaxation processes, give rise to magnetism, and enable new quantum states. The proposed experiments are challenging, and yet the potential benefit is tremendous. The results of our investigations will yield direct insight into the unsolvable dynamics of paradigmatic models. The proposed work will provide a rewarding research experience for young scientists and engineers. Undergraduates, graduate students, and postdoctoral fellows will gain experience with lasers, digital and analog electronics, computer programming and control integration, vacuum technologies, microwave design, building mathematical models, and mechanical workshop skills. Professional development of these highly qualified personnel also includes leadership roles within the research group, travel to and presentations at international conferences, and involvement with public education, tours, and lectures.