Ultracold gases for quantum simulation of non-equilibrium systems

用于非平衡系统量子模拟的超冷气体

• 批准号: RGPIN-2014-06618
• 负责人: Leblanc, Lindsay
• 金额: $ 1.6万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=678917
• 关键词: Ultracold; gases; quantum; simulation; non

In behaviour like superconductivity, where electricity flows with exactly zero loss, relationships between particles at different positions in the system, called "quantum correlations," provide system-wide communication that leads to many-body behaviour. Many-body cooperativity translates quantum effects (usually associated with microscopic particles) to a human scale, where they are accessible and exploitable. The probabilistic nature of quantum mechanics makes predicting these phenomena with calculations on conventional computers feasible only for simple models or small numbers of particles. "Quantum simulation" was proposed by Feynman as an alternative approach. Instead of relying on classical computers to model these behaviours, he reasoned, let quantum mechanics do the work. With real quantum particles whose interactions and environments are tailored to emulate many-body models, calculations are performed by allowing Nature to act according to the laws of quantum mechanics. Solutions are obtained via experimental measurement.**In this research program, we will use laser-cooled ultracold quantum gases as the medium for quantum simulation. At temperatures just billionths of a degree above absolute zero, random motion associated with temperature is all but eliminated, yielding both system-wide quantum correlations and unparalleled control over interactions and environments. These experiments will reveal the essential ingredients leading to a model's quantum many-body order, by examining questions about its energy, ground state, and dynamics. **The Ultracold Quantum Gases Laboratory will focus on many-body systems whose correlations arise as a result of "artificial gauge fields." In these environments, an internal property of the quantum particle, such as "spin," is intrinsically related to an external property, such as momentum. A familiar example of a gauge field is a magnetic field, where these relationships are spatially dependent. Along with engineering artificial magnetic fields, we will implement alternative spin-momentum correlations, some of which are thought to exhibit "topological order:" unique non-local order that is especially good at preserving quantum correlations in the presence of environmental disturbances. Focussing our attention on non-equilibrium properties will provide insight into the factors that control the growth, preservation, and demise of quantum correlations.**This research program makes important contributions to Canada's leadership in quantum technology. By identifying specific conditions under which quantum materials will exhibit robust long-range correlations, this research will provide valuable input to engineers designing new quantum materials and devices. By providing the theoretical physics research community with measurement-based results of quantum many-body models, this research will encourage the pursuit of novel many-body phenomena. In bridging the divide between theoretical conception and practical realization, the research will facilitate the development of next-generation quantum materials, such as those that provide efficient energy transmission with better superconducting materials, or those that offer an exponential increase in computational capacity with devices that process and store resilient quantum correlations. This laboratory will provide young scientists with the opportunity to gain new skills by developing and using precision laser systems, custom electronic controls, and ultrahigh vacuum systems. As they continue their careers, these highly qualified personnel will be able to offer the precision of atomic physics techniques to a variety of industries and research disciplines.

在超导的行为中，电流以零损耗流动，系统中不同位置的粒子之间的关系，称为“量子相关性”，提供了系统范围内的通信，导致了多体行为。多体协作将量子效应（通常与微观粒子有关）转化为人类尺度，在那里它们是可访问和可利用的。量子力学的概率性质使得在传统计算机上通过计算来预测这些现象只能适用于简单模型或少量粒子。“量子模拟”是费曼提出的一种替代方法。他认为，与其依靠经典计算机来模拟这些行为，不如让量子力学来完成这项工作。对于真实的量子粒子，其相互作用和环境是量身定制的，以模拟多体模型，计算是通过允许自然根据量子力学定律来执行的。通过实验测量得到了解决方案。**在本研究项目中，我们将使用激光冷却的超冷量子气体作为量子模拟的介质。在比绝对零度高十亿分之一度的温度下，与温度相关的随机运动几乎完全被消除，从而产生了系统范围内的量子相关性，以及对相互作用和环境的无与伦比的控制。这些实验将通过检查模型的能量、基态和动力学问题，揭示导致模型的量子多体秩序的基本成分。**超冷量子气体实验室将专注于多体系统，其相关性是由“人工规范场”引起的。在这些环境中，量子粒子的内部属性，如“自旋”，与外部属性（如动量）有着内在的联系。一个熟悉的规范场的例子是磁场，其中这些关系是空间依赖的。与工程人工磁场一起，我们将实现替代的自旋动量关联，其中一些被认为表现出“拓扑秩序”：独特的非局部秩序，特别擅长在存在环境干扰的情况下保持量子关联。将我们的注意力集中在非平衡性质上，将使我们深入了解控制量子相关性增长、保存和消亡的因素。**该研究项目为加拿大在量子技术领域的领导地位做出了重要贡献。通过确定量子材料将表现出强大的远程相关性的特定条件，这项研究将为设计新的量子材料和器件的工程师提供有价值的输入。通过为理论物理研究界提供基于量子多体模型的测量结果，本研究将鼓励对新的多体现象的追求。为了弥合理论概念和实际实现之间的鸿沟，该研究将促进下一代量子材料的发展，例如那些使用更好的超导材料提供有效能量传输的材料，或者那些使用处理和存储弹性量子相关性的设备提供指数级增长的计算能力的材料。该实验室将通过开发和使用精密激光系统、定制电子控制和超高真空系统，为年轻科学家提供获得新技能的机会。随着他们继续他们的职业生涯，这些高素质的人才将能够为各种行业和研究学科提供精确的原子物理技术。