Evidence of the presence of opticlike collective modes in a liquid from neutron scattering experiments.
Evidence of the presence of opticlike collective modes in a liquid from neutron scattering experiments.
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中子散射实验证明液体中存在类光学集体模式。
DOI：
10.1103/physrevlett.96.235501
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发表时间：
2006
影响因子：
8.6
通讯作者：
R. Fernández
中科院分区：
文献类型：
--
作者：
F. Bermejo;J. Taylor;S. McLain;I. Bustinduy;J. Turner;M. D. Ruiz;C. Cabrillo;R. Fernández
来自熔点附近液体DF的非弹性中子散射数据显示，除了包含准弹性和严重阻尼声运动的频谱外，还存在一个以约27 meV为中心的强烈非色散带，以及更广泛的更高能量特征。对前一带的观测首次直接验证了分子动力学模拟所预测的液态中集体类光学激发的存在。后者主要对应于由计算机模拟进行的振型特征向量分析所分配的重定向运动。
Inelastic neutron scattering data from liquid DF close to the melting point show, in addition to spectra comprising quasielastic and heavily damped acoustic motions, an intense, nondispersive band centered at about 27 meV along with a broader higher energy feature. Observation of the former band provides the first direct verification of the existence within the liquid state of collective opticlike excitations as predicted by molecular dynamics simulations. The latter corresponds to mainly reorientational motions assigned from mode eigenvector analysis carried out by computer simulations.