闪锌矿结构晶格中的孤子激发(英文)

Analytical Study of Asymmetry Stationary Soliton Excitations in Sphalerite-Structure Lattice with Quartic Anharmonicity

利用多重尺度和准离散近似法研究了双原子链 (相邻两原子质量不同 ,作用力常数交替变化 )中的孤子激发。该模型模拟了闪锌矿结构晶格沿 <111>方向的振动 .考虑二次方和四次方作用势 ,得到了特殊波矢下定态孤子解的表达式 .由于该晶格模型的弱对称性 ,其原子位移分布与文献中广泛研究的一维单原子。

We analytically study soliton excitations in a diatomic chain with different masses and alternating force constants between the nearest neighbors by the means of multiple scales plus quasi discrete approximation method. This model simulates a row of atoms in the <111> direction of a sphalerite structure type of crystal. Considering the harmonic and quartic potential, we obtain the expressions of the stationary soliton solutions at some special wave vectors of the carrier wave (q=±π/a for acoustic mode and q=0,±π/a for optical mode). The configurations of the atomic displacements of this model are asymmetry because of the weak translational asymmetry of this lattice model, which is different from that of those extensively studied one dimensional monatomic, diatomic and diamond structure lattice models in literatures.