Edge state question for a 2-D material and the quantum Hall effect

[Jeff Chen]

I have read some materials about quantum hall effect and know that at the edge of a 2D material , one can linearize the potential V and the linear dispersion relation represents right/left moving fermion. So , Can I say that for a given hamiltonian , if I can linearizae it at edge, then this system has edge state? Thanks!

 

[hokhani]

The existence of edge states in QHE is not very important. One may find edge states in any 2D systems. The important issue is that the electrons on the edges are not backscattered.