Trubitsin V, Ostanin S
Physico-Technical Institute, Ural Branch of RAS, 132 Kirov Strasse, 426001 Izhevsk, Russia.
Phys Rev Lett. 2004 Oct 8;93(15):155503. doi: 10.1103/PhysRevLett.93.155503. Epub 2004 Oct 7.
In studying the lattice dynamics of a strongly anharmonic crystal, we solve a set of nonlinear Langevin equations for interacting oscillators while a multiwell potential is calculated in the displacive limit from the first principles. The model applied to the peculiar vibrations of beta-Zr along [111] allows us to analyze all contributions to the spectral density and their influence on each other. We predict the effect of induced anharmonicity for quick vibrations due to their interaction with intrinsically anharmonic slow vibrations. This effect results in the broadband distribution in energy of inelastic neutron scattering known as the symmetry-forbidden phonon-branch splitting.
在研究强非谐晶体的晶格动力学时，我们求解了一组相互作用振子的非线性朗之万方程，同时从第一性原理在位移极限下计算了多阱势。应用于β-Zr沿[111]方向的特殊振动的模型，使我们能够分析对谱密度的所有贡献及其相互影响。我们预测了由于快速振动与本征非谐慢振动相互作用而导致的诱导非谐性效应。这种效应导致了非弹性中子散射能量的宽带分布，即所谓的对称禁戒声子分支分裂。
