12.2.5 Brillouin zone folding The first Brillouin zone in an energy E versus momentum k plot is limited to π/a (a is the lattice constant) in the principal axes of a primitive cubic lattice. In the diamond lattice cell (eight atoms per cell) the Brillouin zone edge is given by 2π/...
text>The unit cell of a graphite crystal is analyzed by using the basic principle of the harmonic oscillator. For this purpose, we consider the atoms that conform the hexagonal unit cell, connected by small springs. The equation of motion of such cell is established in order to obtain the ...
The efficiency of two different methods for obtaining "special" points useful for Brillouin-zone integrations of periodic functions is compared. We find that for some Bravais lattices (such as body-centered cubic and hexagonal), the method suggested by Monkhorst and Pack leads to different and some...
It is again emphasized that for all cubic lattices the method of Monkhorst and Pack generates not only point sets identical to those obtained by Chadi and Cohen, but also intermediate sets with the same properties. In addition, a comparison of these two methods for the hexagonal lattice reveals...
Rules are given for determining special directions in the Brillouin zone which optimize the description of various physical quantities with 螕 1 -type symmetry. We consider the cubic, hexagonal, tetragonal and trigonal (e.g. Bi) lattice. These rules allow us to construct, in all of momentum ...
The EPC produces the abrupt change in the screening of lattice vibrations by conduction electron, leading to the well-known Kohn anomaly7 manifested by a discontinuity in the derivative of the surface phonons dispersion relation that occurs at certain high symmetry points of the first Brillouin zone...
In your case, it is a square-lattice. The small diagram on your graph tells us that. It is the so-called Reduced Brillouin Zone, while the triangle is the reduced Brillouin triangle. This basic diagram gives us vital information. The square lattice has period or lattice constant of 'a'....