The Emergence of Order in Ultracold Quantum Gases

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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.