Based on the dispersion relation for a wave localised in a thin film of a nonlinear dielectric, which is located on the surface of a topological insulator, we have derived a system of equations that describes the propagation of a surface wave. It is shown that the longitudinal and transverse tangential components of the electric field vector are related due to the nonlinearity of the film and change periodically during propagation. It is found that the rotation period of this vector is determined by the axion charge of the topological dielectric and the nonlinear susceptibility of the thin film.

中文翻译：

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拓扑绝缘体表面薄介电膜中的非线性波

基于位于拓扑绝缘体表面的非线性电介质薄膜中波的色散关系，我们推导出了描述表面波传播的方程组。结果表明，由于薄膜的非线性，电场矢量的纵向和横向切向分量是相关的，并且在传播过程中会发生周期性变化。发现该向量的旋转周期由拓扑电介质的轴子电荷和薄膜的非线性磁化率决定。