Electronic Band structure is useful tools for examining a material . One can deriving the band gap, size, position, direct/indirect nature. One can also analyse the character of the bands and learn about which atoms/bonds are involved. Now I go through a paper which mentioned that material is an-isotropic by giving the argument of band structure. I want to know how can we know such information from band structure. Your suggestion and guideline would be highly appreciated.
You need to be more specific. "Isotropic" could mean the energy bands do not show any dimensional preference, or in other words, they disperse similarly along all crystalline directions (You get this behavior for example in bulk-Cu. In contrast, in a quasi-2D system like transition metal dichalcogenides you get anisotropic bands dispersions).
Alternatively it could also mean the system is magnetically isotropic, rather than having a particular easy axis. Anyway there are many ways to interpret this generic term ....
Hello Mohammad,
if we say - a band structure is isotropic - then it means isotropic in k-space. Isotropic in the momentum space doesn't automatically mean isotropic in local space.
With regard
R. Mitdank
In general isotropic means in physics that a certain quantity does not depend on direction. To answer your question requires at least that you are more specific about the quantity you are interested in. Any quantity that cannot be linked in a meaningful way to the bandstructure goes already beyond what you are asking. A bandstructure is the electronic structure of a purely crystalline solid and is governed by its translational symmetry. As such even crystalline solids are never isotropic. The first Brillouin zone e.g. can never be rotated over an arbitrary angle, such that the result coincides with the original. Most simple metals however have an E(k) being almost isotropic and can be approximated that way. If a physical quantity has a prominent anisotropic behaviour, it is very difficult to link that anisoptropy to a common type of bandstructure calculation. It would go too far to specify this in more detail here. Mostly one will hit upon the inherent assumptions and hence limitations of the bandstructure or more general of the electronic structure modelling.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Atomic, Molecular and Optical Physics
- Atoms