Experimental Studies of Intrinsic Nanoscale Localization for Low Lying Excitations in Solids

固体中低位激发本征纳米尺度局域化的实验研究

基本信息

批准号：
9979483
负责人：
Albert Sievers
金额：
$ 36万
依托单位：
Cornell University
依托单位国家：
美国
项目类别：
Continuing grant
财政年份：
1999
资助国家：
美国
起止时间：
1999-12-01 至 2003-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9979483&HistoricalAwards=false
关键词：
Experimental Studies Intrinsic Nanoscale Localization

项目摘要

9979483SieversA recent advance of the theory of nonlinear excitations in discrete lattices was the discovery that some localized vibrations in perfectly periodic lattices can be stabilized in bulk crystals, at their surfaces or at their edges by lattice discreteness. Because these excitations display nanoscale dimensions and are predicted to move through the lattice their experimental generation and observation is of paramount interest. To this end the proposed experimental study of nonlinear spin lattice systems has definite advantages because the dissipation of spin waves in magnetic materials is weak compared to that of lattice vibrations in crystals. Consequently, large amplitude excitations are more readily obtainable and one objective of this project is to examine experimentally the physical properties of such localized excitations in antiferromagnets. In addition to generation and detection it is also important to explore the propagation and transport properties of intrinsic localized modes. Depending on the successes found for magnetic excitations, experimental studies of intrinsic localization associated with macroscopic and quantum systems will also be explored. The general feature that such localization in periodic lattices depends only on nonlinearity plus discreteness ensures that graduate and undergraduate students working in this area will have training in nonlinear dynamics spanning a variety of length scales, ranging from the nano- to the macroscopic one.%%%This experimental program is directed at probing the underlying simplicity of the dynamics of nonlinear periodic physical systems, which range from studies of large amplitude excitations in atomic lattices to those in micro electrical mechanical arrays. Graduate and undergraduate students working in this new research area will have training in condensed matter nonlinear dynamics involving all the technologically important length scales.***

9979483Sievers 离散晶格非线性激发理论的最新进展是发现完美周期性晶格中的一些局部振动可以通过晶格离散性在块体晶体中的表面或边缘处稳定。由于这些激发显示出纳米级尺寸，并且预计将穿过晶格，因此它们的实验生成和观察至关重要。为此，所提出的非线性自旋晶格系统的实验研究具有一定的优势，因为磁性材料中自旋波的耗散与晶体中晶格振动的耗散相比较弱。因此，更容易获得大幅度激励，该项目的目标之一是通过实验检查反铁磁体中此类局部激励的物理性质。除了生成和检测之外，探索固有局域模式的传播和传输特性也很重要。根据磁激发的成功，还将探索与宏观和量子系统相关的固有局域化的实验研究。周期晶格中的这种局域化仅依赖于非线性和离散性的一般特征确保了在这一领域工作的研究生和本科生将接受跨越各种长度尺度（从纳米到宏观）的非线性动力学训练。%%该实验计划旨在探讨非线性周期性物理系统动力学的基本简单性，其范围从原子晶格中的大幅激发研究到微机电阵列中的研究。在这个新研究领域工作的研究生和本科生将接受凝聚态非线性动力学方面的培训，涉及所有技术上重要的长度尺度。***