论文标题
1D，2D和3D材料中晶格动力学的一般不变性和平衡条件
General invariance and equilibrium conditions for lattice dynamics in 1D, 2D, and 3D materials
论文作者
论文摘要
振动模式的长波长行为在载体传输，声子辅助的光学特性，超导性以及材料的热机械和热电特性中起着核心作用。在这里，我们提出了晶格电位的一般不变性和平衡条件。这些允许在低维材料中恢复弯曲声子的二次分散，与长波长弯曲模式的现象学模型一致。我们还证明，对于任何低维材料，弯曲模式可以在真空方向上具有纯粹的平面极化，而在长波长极限中可以具有二次散布。此外，我们提出了一种有效的方法，可以治疗具有不变的有效电荷的晶体中的不变性条件，其中远程偶极 - 偶极相互作用会导致对晶格潜力和应力张量的贡献。我们的方法成功地应用于158种二维材料的声子分散剂，突出了其在低维材料的语音介导特性的研究中的关键相关性。
The long-wavelength behavior of vibrational modes plays a central role in carrier transport, phonon-assisted optical properties, superconductivity, and thermomechanical and thermoelectric properties of materials. Here, we present general invariance and equilibrium conditions of the lattice potential; these allow to recover the quadratic dispersions of flexural phonons in low-dimensional materials, in agreement with the phenomenological model for long-wavelength bending modes. We also prove that for any low-dimensional material the bending modes can have a purely out-of-plane polarization in the vacuum direction and a quadratic dispersion in the long-wavelength limit. In addition, we propose an effective approach to treat invariance conditions in crystals with non-vanishing Born effective charges where the long-range dipole-dipole interactions induce a contribution to the lattice potential and stress tensor. Our approach is successfully applied to the phonon dispersions of 158 two-dimensional materials, highlighting its critical relevance in the study of phonon-mediated properties of low-dimensional materials.
