The Emergence of Order in Ultracold Quantum Gases

超冷量子气体中有序的出现

• 批准号: RGPIN-2016-06323
• 负责人: Thywissen, Joseph
• 金额: $ 5.39万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=616234
• 关键词: Emergence; Order; Ultracold; Quantum; Gases

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. We propose experiments with ultracold atoms that study the dynamics of emerging order. Over the past decade, we have learned how to study a fermionic isotope of neutral potassium, which can emulate the behaviour of electrons in solids, or even explore scenarios inaccessible with solid materials. In either case, the advantage of our “quantum emulation” approach using cold atoms in is an unprecedented ability to tune and characterise the sample. This leaves no room for uncertainty about the model we explore; so that any phenomena or behaviour observed has a direct connection to the model. Our proposed research will address three open questions about non-equilibrium quantum dynamics. A first series of experiments explores the rate at which spin diffusion occurs in a strongly interacting Fermi gas. We hope to resolve a current debate regarding the effect of dimensionality on dissipation. A second series of experiments explore the emergence of p-wave correlations. We aim to create an ultracold p-wave material with unique and controllable properties. Excitations of p-wave superfluids include Majorana states, widely sought for their promise in quantum information processing. A third line of exploration uses a newly developed microscope to search for magnetic ordering of atoms in a crystal of light. Success of this research program would elucidate how inter-particle interactions limit relaxation processes, give rise to magnetism, and enable new superfluid states. Addressing these issues with cold atoms is a type of high-risk, high-reward experiment, because the experiments are challenging and the theory is poorly understood, and yet the potential benefit is tremendous: the results of our investigations will yield direct insight into the unsolvable dynamics of paradigmatic models.

我们周围的世界在不断变化。从这些动态中，可以出现平衡秩序。但是，我们认为是生命本身的日常动力学不可能存在于平衡状态，因为（例如）离子浓度的梯度驱动神经中的动作电位。非平衡态动力学的研究在早期宇宙学、经济市场动力学、重离子碰撞中的夸克-胶子等离子体以及超导体的电阻率等领域都有广泛的应用。 我们提出了超冷原子的实验，研究新兴秩序的动力学。在过去的十年中，我们已经学会了如何研究中性钾的费米同位素，它可以模拟固体中电子的行为，甚至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“量子仿真”方法的优点是具有前所未有的调谐和重定位样品的能力。这使得我们所探索的模型没有不确定性的余地;因此，观察到的任何现象或行为都与模型有直接的联系。 我们提出的研究将解决非平衡量子动力学的三个开放问题。第一系列的实验探讨了自旋扩散发生在强烈相互作用的费米气体的速率。我们希望解决目前关于维数对耗散的影响的争论。第二个系列的实验探索p波相关性的出现。我们的目标是创造一种具有独特和可控特性的超冷p波材料。p波超流体的激发包括马约拉纳态，广泛寻求它们在量子信息处理中的前景。第三条探索线使用新开发的显微镜来寻找光晶体中原子的磁性排序。 这项研究计划的成功将阐明粒子间的相互作用如何限制弛豫过程，产生磁性，并使新的超流体状态成为可能。用冷原子解决这些问题是一种高风险、高回报的实验，因为实验具有挑战性，理论也不太清楚，但潜在的好处是巨大的：我们的研究结果将直接洞察范式模型的不可解动力学。