Experimental Studies of Nanoscale Energy Localization in Periodic Condensed Matter Systems

周期性凝聚态体系纳米级能量局域化的实验研究

• 批准号: 0301035
• 负责人: Albert Sievers
• 金额: --
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-15 至 2007-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0301035&HistoricalAwards=false
• 关键词: Experimental; Studies; Nanoscale; Energy; Localization

This individual investigator award supports a research program focused on the experimental investigation of nonlinear nanoscale localization phenomena and discrete pattern formation in condensed matter physics. One way to produce such intrinsic energy localization over a nanoscale region is by making use of the modulational instability of specific large amplitude nonlinear plane wave excitations. To better understand the pathways from plane wave instability to nanoscale energy localization in crystals, three different classes of experiments will be carried out: (a) Intrinsic localized modes (ILMs) in 1D micromechanical arrays will make possible the study of the long time production of monochromatic energy localization phenomena. (b) Intrinsic localized spin wave modes in classical 1D-like antiferromagnetic crystals will be studied in an attempt to observe the newly predicted localized spin flop, which represents a more localized and larger energy excitation than does an ILM. (c) Intrinsic nanoscale energy localization in quantum antiferromagnets and also in soft mode paraelectric crystals will be investigated using high-intensity broadband THz radiation produced at the Jefferson Laboratory. In carrying out nonlinear experiments coupled with numerical simulations both graduate and undergraduate students will develop expertise in this developing interdisciplinary field. Both nonlinearity and lattice discreteness have played important roles in many branches of physics. The traditional approach in condensed matter physics has been to treat these two items separately. Recently it has been predicted and realized that completely new kinds of dynamical phenomena occur in strongly nonlinear discrete systems. For example, large amplitude long wavelength vibrations in a solid can rapidly cascade down and localize at the atomic scale with a large increase in the vibrational amplitude. The resulting discrete nanoscale patterns in the crystal are predicted to give rise to different physical states. This experimental research program explores such new phenomena. The rapid growth of scientific activity in nonlinear energy localization behavior has shown there are a variety of areas where these effects may play a role, such as friction, and crack propagation. Still other developing areas involve somewhat larger length scales such as optical switches, nonlinear photonic crystal waveguides, periodic electrical Josephson junction arrays, micro-electrical-mechanical silicon systems, and, at the largest scale, the localization within multibunch modes in high energy accelerators. Graduate and undergraduate students working on this project will receive training in nonlinear dynamics in condensed matter systems involving technologically important length scales.

该个人研究者奖支持一项研究计划，重点介绍了非线性纳米级定位现象的实验研究和冷凝物理学中的离散模式形成。在纳米级区域产生这种内在能量定位的一种方法是利用特定的大幅度非线性平面波激发的调节不稳定性。为了更好地了解从平面波不稳定性到晶体中纳米级能量定位的途径，将进行三种不同类别的实验：（a）1D微力阵列中的内在局部模式（ILMS）将使长期生产的研究可能会导致单色能量定位现象。 （b）将研究经典1D样抗铁磁晶体中的内在局部旋转波模式，以尝试观察新预测的局部旋转失调，这代表了与iLM相比，它代表了更具局部和更大的能量激发。 （c）将使用杰斐逊实验室产生的高强度宽带THZ辐射研究量子抗铁磁铁和软模式降压晶体中的纳米级能定位。在进行非线性实验以及研究生和本科生的数值模拟时，将在这个发展中的跨学科领域中发展专业知识。 非线性和晶格离散性在许多物理学分支中都起着重要作用。凝结物理学的传统方法是分别处理这两个项目。最近，已经预测并意识到，在强烈的非线性离散系统中发生了全新的动态现象。例如，固体中的大幅度长波长振动可以快速降落并在原子尺度上定位，并且振动幅度大大增加。预计晶体中产生的离散纳米级模式会产生不同的物理状态。该实验研究计划探讨了这种新现象。非线性能量定位行为中科学活动的快速增长表明，这些影响可能起作用，例如摩擦和裂纹传播。还有其他发展区域还涉及较大的长度尺度，例如光学开关，非线性光子晶体波导，周期性电气约瑟夫森连接阵列，微电机械硅系统，以及最大的尺度，在高能加速器中的多次量化模式中的本地化。 从事该项目的研究生和本科生将接受涉及技术重要长度尺度的冷凝物质系统中非线性动力学的培训。