Description of Crystal Lattices

The Crystal Lattice

晶体晶格

Most solids have periodic arrays of atoms which form what we call a crystal lattice. Amorphous solids and glasses are exceptions. The existence of the crystal lattice implies a degree of symmetry in the arrangement of the lattice, and the existing symmetries have been studied extensively.

大多数固体具有周期性排列的原子，形成我们称之为晶体 lattice 的结构。非晶固体和玻璃是例外。晶体 lattice 的存在表明原子排列中存在一定程度的对称性，而现有的对称性已得到广泛研究。

One of the implications of the symmetric lattice of atoms is that it can support resonant lattice vibration modes. These vibrations transport energy and are important in the thermal conductivity of non-metals, and in the heat capacity of all solids.

原子对称晶格的一个结果是它可以支持共振晶格振动模式。这些振动传输能量，并在非金属的热传导以及所有固体的热容量中起重要作用。

Lattice Vibrations

晶格振动

The existence of a periodic crystal lattice in solid materials provides a medium for characteristice lattice vibrations.

固体材料中存在周期性晶体晶格，为特征晶格振动提供了介质。

On the scale of the lattice spacing, these vibrational modes are quantized, with the quantum of lattice vibration being called a phonon. Treating the lattice vibrations quantum mechanically led to the Einstein model and the Debye model of specific heat.

在晶格间距尺度上，这些振动模式是量子化的，其量子化振动称为声子。将晶格振动量子化处理导致了爱因斯坦模型和德拜模型。

In the BCS Theory of superconductivity, electron pairs in the low-temperature material couple by means of phonons to produce Cooper pairs. The phonon coupling produces a bound state which cannot be excited by the available thermal energy and therefore move without resistance through the crystal lattice.

在超导体的BCS理论中，低温材料中的电子对通过声子耦合形成库珀对。声子耦合产生了一个无法被可用热能激发的束缚态，因此这些电子对在晶体晶格中运动时不会遇到电阻。

Lattice vibrations can also interact with light to produce scattering called Brillouin scattering, which is used in laser spectroscopy.

晶格振动也可以与光相互作用，产生称为布拉格散射的散射现象，该现象用于激光光谱学。