共查询到20条相似文献,搜索用时 234 毫秒
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利用Landau-Lifshitz 方程,研究了具有非均匀交换各向异性的半无限大铁磁体的非线性表 面自旋波理论。导出了部分钉扎纯交换铁磁介质的磁化强度所满足的边界条件和非线性表面 自旋波的色散关系,并获得了自旋波振幅沿z方向驻波的一维非线性Schrdinger方程和包 络振幅沿平面传播的二维非线性Schrdinger方程,结果表明铁磁体磁化强度的包络振幅随时空变化的性质是由二维非线性Schrdinger方程决定的。因此预言铁磁介质的表面非线性激发应是二维孤波的形式。对于弱非线性表面自旋波,对非线性Schrdinger方程存在孤子形式解的可能性作了讨论.
关键词:
表面自旋波
Landau-Lifshitz方程
非线性Schrdinger方程
孤子 相似文献
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蛋白质分子链的非线性激发的孤子模型的一个改进解 总被引:1,自引:1,他引:0
通过仔细考察蛋白质分子链中体系运动方程的非线性项,得到了一个与通常非线性Schrdinger方程不同的修正的非线性Schrdinger方程,并求得了一个改进孤子解. 相似文献
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由loop代数的一个子代数出发,构造了一个线性等谱问题,再利用屠格式计算出了一类Liouvelle意义下的可积系统及其双Hamilton结构,作为该可积系统的约化,得到了著名的Schrdinger方程和mKdV方程,因此称该系统为S-mKdV方程族.根据已构造的的子代数,又构造了维数为5的loop代数的一个新的子代数,由此出发设计了一个线性等谱形式,再利用屠格式求得了S-mKdV方程族的一类扩展可积模型.利用这种方法还可以求BPT方程族、TB方程族等谱系的扩展可积模型.因此本方法具有普遍应用价值.最后作为特例,求得了著名的Schrdinger方程和mKdV方程的可积耦合系统. 相似文献
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在光孤子通信和Bose-Einstein凝聚体动力学研究中,求解广义非线性Schrdinger方程是一个重要的研究方向.稳定的孤子模式具有潜在的应用,可为实验技术的实现提供依据.本文引进一种相似变换,将变系数非线性Schrdinger方程转化成非线性Schrdinger方程,并利用已知解深入研究变系数非线性Schrdinger方程解的单孤子解、两孤子解和连续波背景下的孤子解.同时通过选择不同的具体参数,给出它们的图像分析和相应的讨论. 相似文献
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在光孤子通信和Bose-Einstein凝聚体动力学研究中,求解广义非线性Schr(o)dinger方程是一个重要的研究方向.稳定的孤子模式具有潜在的应用,可为实验技术的实现提供依据.本文引进一种相似变换,将变系数非线性Schr(o)dinger方程转化成非线性Schr(o)dinger方程,并利用已知解深入研究变系数非线性Schr(o)dinger方程解的单孤子解、两孤子解和连续波背景下的孤子解.同时通过选择不同的具体参数,给出它们的图像分析和相应的讨论. 相似文献
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量子通信是一个量子密钥分发过程,目前采用的通信技术严重制约了量子密钥分发的比特率.将多输入多输出(MIMO)技术应用于量子通信系统,提高量子密钥分发的比特率,促进量子通信向高速大容量发展.然而,量子场本身不可避免地存在量子噪声约束容量的增长,限制了可利用空间资源,即空间自由度.文中采用光子场的量子化和满足Schrdinger方程条件的电磁场波动方程推导出MIMO量子信道的空间自由度上限,为开发稳健的MIMO量子通信空时处理算法和优化设计高性能MIMO量子通信系统提供理论基础和技术支持.
关键词:
多输入多输出
量子密钥分发
Schrdinger方程
光子场的量子化 相似文献
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构筑了一个9个残基长度的短肽段库,根据短肽段的结构把它们分成不同的簇,用卡方分析每个簇,鉴别不同位点之间的相关性.同时还构筑了一个序列比对的评分函数,这个评分函数不但包含单个位点的信息,也包含不同位点之间相关性的信息.结果表明, 位点之间的相关性能够提供一些新颖的信息,这些信息一般都与短肽段不同位点之间的相互作用有关,相关性信息的引入能够明显的提高短肽段结构的预测准确度. 相似文献
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John E. Roberts 《Communications in Mathematical Physics》1974,37(4):273-286
In a dilatation-invariant theory it is shown that there is a unique locally normal dilatation-invariant state. Furthermore a gauge transformation of a local algebra cannot be implemented by a unitary operator from the local algebra. If the local field algebras are factors then so are the local observable algebras. The superselection structure of the theory can be determined locally. 相似文献
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Detecting local communities in real-world graphs such as large social networks, web graphs, and biological networks has received a great deal of attention because obtaining complete information from a large network is still difficult and unrealistic nowadays. In this paper, we define the term local degree central node whose degree is greater than or equal to the degree of its neighbor nodes. A new method based on the local degree central node to detect the local community is proposed. In our method, the local community is not discovered from the given starting node, but from the local degree central node that is associated with the given starting node. Experiments show that the local central nodes are key nodes of communities in complex networks and the local communities detected by our method have high accuracy. Our algorithm can discover local communities accurately for more nodes and is an effective method to explore community structures of large networks. 相似文献
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Thomas L. Beck 《Journal of statistical physics》2011,145(2):335-354
In the quasichemical theory of molecular solutions, the hydration free energy is spatially partitioned in a three-step thermodynamic
process: cavity formation, solute insertion into the cavity, and relaxation of the cavity constraint. In the alternative local
molecular field theory that focuses on the relationship of fluid structure and forces, the interaction energies are directly
partitioned into local and far-field components; a restructured local potential incorporates information from the far-field
interactions at the mean-field level. Here the quasichemical and local molecular field theories are related via energetic
partitioning of the potential distribution theorem free energy. The resulting theory leads to a free energy division in which
the local contribution requires direct evaluation, but the far-field component can be accurately estimated at the Gaussian
level. A numerical approach for computing hydration free energies is developed that employs interaction energy distributions
from several sampling states. Classical model problems of nonpolar, polar, and ionic hydration are presented to illustrate
the theory. Extensions of the theory for estimating free energies at the quantum level are also discussed. 相似文献
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Manfred Wollenberg 《Reports on Mathematical Physics》1985,22(3):409-417
It is shown that quantum fields which are relatively local to a given local algebra of observables can be recovered from this algebra. 相似文献
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《Physics letters. A》2020,384(15):126308
We investigate the dynamics of a susceptible-infected-susceptible (SIS) epidemic model on adaptive (co-evolutionary) networks. In most of these models, the rewiring mechanism is based on information known globally. Here, we propose local rewiring where rewiring decision is based on local information around a given node. Our results show that there are phase overlaps between local and global rewirings. The results suggest that under a certain circumstance, even with limited local information, outcomes from both rewirings are statistically similar. Furthermore, we found that the epidemic threshold does not depend on the amount of information. This could be useful for planned intervention of an epidemic spreading using minimal information. 相似文献
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We find that the global symbolic dynamics of a diffusively coupled map lattice is well approximated by a very small local model for weak to moderate coupling strengths. A local symbolic model is a truncation of the full symbolic model to one that considers only a single element and a few neighbors. Using interval analysis, we give rigorous results for a range of coupling strengths and different local model widths. Examples are presented of extracting a local symbolic model from data and of controlling spatiotemporal chaos. 相似文献
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The EXAFS method has been used for investigating the local structures of ferric oxyhydroxides which are reaction products formed on an iron surface exposed to air or immersed in salt water. Fe K EXAFS spectra of two references of ferric oxyhydroxides, i.e. goethite and lepidocrocite, which are often detected as components of reaction products, have been also studied for comparison thereof. The two reference oxyhydroxides demonstrated different EXAFS spectra, which are interpreted based on the atomic local structures. Fe K EXAFS spectra and their radial distribution functions of the reaction products formed on an iron surface have been compared with those of the reference oxyhydroxides. This comparison shows that the first and second nearest neighboring structures around ferric ions in the reaction products are different from those of the two references. These results indicate that the local structures around ferric ions in the reaction products are disordered, although the atomic local structures of Fe–O may be described as being local structural units. 相似文献