Probing novel out-of-equilibrium dynamics and new phases in quantum systems

探索量子系统中新颖的非平衡动力学和新相

• 批准号: RGPIN-2019-06465
• 负责人: Agarwal, Kartiek
• 金额: $ 2.11万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=762400
• 关键词: Probing; novel; out; equilibrium; dynamics

Traditionally, the study of condensed matter physics has concerned itself with investigations of the properties of materials in equilibrium. This very fruitful effort has resulted in the discovery and classification of many exotic quantum phases of matter such as superconductors, quantum Hall insulators, and more recently topological materials, all of which have potentially immense technological implications. More recently however, and bolstered with the advent of new technologies to artificially engineer and manipulate quantum matter (for simulating complex materials and quantum computing), a new line of questioning focussed on properties of quantum matter out of equilibrium has gained impetus. In conventional materials, electrons are coupled to vibrations of the lattice, impurities and other sources of dissipation. As a result, they exchange energy and momentum with these sources of noise and equilibrate rapidly on nanosecond timescales. Thus, investigating quantum dynamics and out-of-equilibrium properties is extremely challenging in conventional materials. However, for a quantum simulator or computer to function as desired, it is absolutely necessary that it is immune to such decoherence. Today, a number of extremely promising candidates for quantum computing exist, each of which is isolated from noise to different degrees and has its own challenges. These include defects in diamond, atoms cooled to nano Kelvin temperatures in magnetoelectric traps, quantum bits engineered using superconducting junctions, and so on. To make further progress in using these devices to fulfill the challenges and promises of quantum computing, we need to understand precisely how quantum matter behaves in non-equilibrium settings. Can quantum matter be protected, somehow, from sources of noise and decoherence? Do all quantum systems thermalize by themselves, even in the absence of external noise, and if not all, what are the conditions that engender long-time non-equilibrium behavior? How can one find solutions to problems impossible to solve on a classical computer using quantum simulators? Can one induce favorable properties in quantum systems that would otherwise be impossible to find in equilibrium? Is there a classification of matter out-of-equilibrium as there is for matter in equilibrium? Finally, how can one probe such non-equilibrium behavior experimentally; in particular, what protocols can be devised to measure such properties? Our research is centered around solving precisely such problems which occur at the intersection of being practically relevant questions pertaining to the advancement of quantum simulators, and which have the potential to theoretically advance our knowledge of quantum non-equilibrium physics. We will deploy novel analytical and state-of-the-art numerical techniques, and work closely with experimental groups around Canada and globally to make progress on these problems.

传统上，凝聚态物理学的研究关注的是物质在平衡状态下的性质。这一卓有成效的努力导致了许多奇异的量子相物质的发现和分类，如超导体，量子霍尔绝缘体，以及最近的拓扑材料，所有这些都具有潜在的巨大技术意义。然而，最近，随着人工工程和操纵量子物质（用于模拟复杂材料和量子计算）的新技术的出现，一个新的问题集中在量子物质的平衡特性上，这一问题得到了推动。 在传统材料中，电子与晶格的振动、杂质和其他耗散源耦合。因此，它们与这些噪声源交换能量和动量，并在纳秒时间尺度上迅速平衡。因此，研究量子动力学和非平衡性质在传统材料中极具挑战性。然而，为了使量子模拟器或计算机按预期运行，它绝对需要不受这种退相干的影响。今天，存在许多非常有前途的量子计算候选者，每一个都在不同程度上与噪声隔离，并有自己的挑战。这些包括金刚石中的缺陷、在磁电阱中冷却到纳米开尔文温度的原子、使用超导结设计的量子比特等等。为了在使用这些设备来实现量子计算的挑战和承诺方面取得进一步的进展，我们需要精确地理解量子物质在非平衡环境中的行为。量子物质能以某种方式免受噪音和退相干的影响吗？所有的量子系统都是自己热化的吗，即使没有外部噪音，如果不是所有的话，产生长时间非平衡行为的条件是什么？如何使用量子模拟器找到在经典计算机上无法解决的问题的解决方案？人们能否在量子系统中诱导出在平衡态中不可能发现的有利性质？是否有一种对非平衡态物质的分类，就像对平衡态物质的分类一样？最后，如何能探测这种非平衡行为的实验;特别是，什么协议可以设计来测量这样的属性？我们的研究集中在精确解决这些问题，这些问题发生在与量子模拟器的进步有关的实际相关问题的交叉点上，并且有可能在理论上提高我们对量子非平衡物理学的认识。我们将部署新的分析和最先进的数值技术，并与加拿大和全球各地的实验小组密切合作，以在这些问题上取得进展。