An edge state is a state of a material that is confined to the edges or boundaries of a 2-dimensional material. These states arise due to the quantum confinement of electrons in the material, resulting in unique electronic properties at the edges.
The quantum Hall effect is a phenomenon in which the electrical resistance of a 2-D material changes in discrete steps when a strong magnetic field is applied. This effect is caused by the presence of edge states, which are responsible for conducting electricity along the edges of the material.
Edge states play a crucial role in the electronic properties of 2-D materials. They can exhibit unique behavior, such as unidirectional flow of electrons, and can be used to engineer new electronic devices with enhanced functionality.
No, edge states are only observed in materials that exhibit a quantum Hall effect, such as graphene, topological insulators, and certain semiconductors. These materials have a unique band structure that allows for the formation of edge states.
Edge states can significantly influence the transport properties of 2-D materials. They can lead to the suppression of backscattering and dissipation, resulting in highly efficient and robust electronic transport. This makes them promising candidates for future electronic devices.