Disorder and Dynamics in Solids and Superfluids

固体和超流体中的无序和动力学

• 批准号: 0906780
• 负责人: Paul Goldbart
• 金额: $ 28.5万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0906780&HistoricalAwards=false
• 关键词: Disorder; Dynamics; Solids; Superfluids

TECHNICAL SUMMARYThis award supports theoretical research and education on nonequilibrium statistical physics spanning from classical to quantum systems. The research will focus on three areas: the structure and dynamics of random solids, non-equilibrium states and avalanching in superfluid helium flowing through nanopore arrays, and the structure and dynamics of ordering in laser-driven atomic systems housed in photonic cavities. Random solids are materials created via the permanent chemical bonding of randomly selected constituents, and are well exemplified by vulcanized rubber. This bonding creates a new state of matter, which acquires a nonzero shear modulus and spatial localization of its constituents - but with no long-range crystallinity. The PI's past work of has led to a fairly refined understanding of the static equilibrium structure and elasticity of simple random solids. The PI will develop an understanding of dynamics in simple random solids and their parent liquids, and when the materials exhibit long- or short-range liquid crystallinity, how this ordering interacts with the structure of the random solid. To accomplish these goals powerful statistical-mechanical tools will be applied that properly and instructively account for the deeply random chemical-level architecture that such materials possess. Motivated by beautiful experiments due to the Berkeley group, the PI plans to address the nature of helium superflow through arrays of thousands of nanoscale ?Josephson pores? connecting two reservoirs. The PI?s recent work argues that the qualitative nature of the flow depends crucially on a ?hidden? competition between superfluid "elasticity" and disorder, which arises from pore-to-pore variability. This work suggests that collective system-spanning "ruptures" in the superflow can occur at weak, but not at strong, disorder, these regimes being separated by a non-equilibrium phase transition that has antecedents in several condensed-matter and geophysical settings. The PI plans to construct a detailed theory of helium superflow through nanopore arrays that incorporates the effects of fluctuations and experiment geometry, and builds a statistical characterization of the flow dynamics. Laser-driven atomic gases, trapped in high-finesse optical cavities are expected to undergo fascinating nonequilibrium quantum phase transitions to states of strong, spontaneous organization among the atoms, which self-consistently populate either the even or the odd anti-nodes of certain modes of the cavity radiation. For suitably designed cavities, these transitions are expected to be accompanied by strong fluctuations in the atomic organization, which will imprint themselves on the spatial and temporal correlations of the light leaking from the cavity. The PI aims to apply a wide array of condensed matter techniques in developing a thorough picture of the ordering, its steady-state fluctuations, and the rich kinetics via which this nonequilibrium steady state is achieved. NONTECHNICAL SUMMARYThis award supports a theoretical research and education program across hard and soft condensed matter physics with the study of systems and materials that are out of equilibrium and in which randomness plays an important role. The PI will conduct research in three areas. In the first the PI will study the properties of random solids ? materials made of a network of long chain-like molecules in which the chains are linked to each other at random places. In the second area the PI will study the flow of superfluid helium, a liquid at low temperature with remarkable properties such as the ability to flow without dissipation, through an array of nanoscale pores. In the third area the PI will study the nonequilbrium phases of atomic gases in an optical cavity and transitions among them that arise when a laser is applied. These three areas of research advance the field of statistical physics which seeks to discover universal principles that characterize systems that are far from equilibrium and link seemingly unrelated systems. From a physical point of view, living things provide perhaps the most familiar example of systems that are far from equilibrium. This is fundamental research that will advance our understanding of systems and materials that are far from equilibrium.

该奖项支持从经典到量子系统的非平衡统计物理的理论研究和教育。 研究将集中在三个领域：随机固体的结构和动力学，超流氦流经纳米孔阵列的非平衡态和雪崩，以及光子腔中激光驱动原子系统的结构和动力学。随机固体是通过随机选择的成分的永久化学键合产生的材料，并且通过硫化橡胶很好地举例说明。这种键合创造了一种新的物质状态，它获得了非零的剪切模量和其组分的空间局部化-但没有长程结晶。PI过去的工作导致了对简单随机固体的静态平衡结构和弹性的相当精细的理解。PI将发展在简单的随机固体及其母液的动态的理解，以及当材料表现出长或短范围的液晶性，这种排序如何与随机固体的结构相互作用。为了实现这些目标，强大的物理机械工具将被应用，这些工具将适当地和连续地解释这些材料所具有的深度随机化学水平结构。由于伯克利小组的美丽实验的动机，PI计划通过数千纳米的阵列来解决氦超流的性质？约瑟夫森毛孔？连接两个水库。私家侦探？的最近的工作认为，流动的定性性质取决于一个关键？隐藏？超流体“弹性”和无序之间的竞争，这是由孔隙到孔隙的变化引起的。这项工作表明，集体系统跨越“破裂”的超流可以发生在弱，但不是在强，无序，这些制度被分离的非平衡相变，在几个凝聚态物质和地球物理环境的前身。PI计划通过纳米孔阵列构建氦超流的详细理论，该理论结合了波动和实验几何形状的影响，并建立了流动动力学的统计特征。激光驱动的原子气体，被困在高精细光学腔中，预计将经历迷人的非平衡量子相变到原子之间的强自发组织状态，这些状态自洽地填充腔辐射的某些模式的偶或奇的腹点。对于适当设计的腔，这些跃迁预计将伴随着原子组织中的强烈波动，这将对从腔泄漏的光的空间和时间相关性产生影响。PI的目的是应用广泛的凝聚态技术，开发一个完整的图片的顺序，其稳态波动，并通过这种非平衡稳态实现丰富的动力学。非技术性总结该奖项支持硬和软凝聚态物理学的理论研究和教育计划，研究系统和材料，这些系统和材料处于不平衡状态，随机性在其中起着重要作用。PI将在三个方面进行研究。在第一个PI将研究随机固体的性质？由长链状分子网络构成的材料，其中链在随机位置彼此连接。在第二个领域，PI将研究超流氦的流动，超流氦是一种在低温下具有显着特性的液体，例如通过纳米级孔阵列流动而不耗散的能力。在第三个领域中，PI将研究光学腔中原子气体的非平衡相位以及应用激光时出现的它们之间的跃迁。这三个研究领域推动了统计物理学领域的发展，该领域旨在发现表征远离平衡的系统和连接看似无关的系统的普遍原理。从物理学的角度来看，生物可能是最熟悉的远离平衡的系统的例子。这是一项基础研究，将促进我们对远离平衡的系统和材料的理解。