What are topological surface states?

Topological Surface States (TSS) represent new types of two dimensional electron systems with novel and unprecedented properties distinct from any quantum Hall-like or spin-Hall effects.

What are edge states?

The edge/surface states consist of pairs of states which have opposite spins and propagate in the opposite directions; they are degenerate by the Kramers theorem, and form pure spin currents as has been discussed in the context of spin Hall effect [6, 7].

What is meant by surface state?

Surface states are electronic states found at the surface of materials. The termination of a material with a surface leads to a change of the electronic band structure from the bulk material to the vacuum. In the weakened potential at the surface, new electronic states can be formed, so called surface states.

What is a topological state?

A topologically ordered state is a state with complicated non-local quantum entanglement. The non-locality means that the quantum entanglement in a topologically ordered state is distributed among many different particles. As a result, the pattern of quantum entanglements cannot be destroyed by local perturbations.

Is graphene a topological material?

Graphene has been successfully converted into a unique state of topological insulator for the first time. Graphene, a two-dimensional material with single atomic layer composed only of carbon, has attracted attention as a next-generation electronic device material because of its high thermal and electric conductivity.

Is graphene a topological?

The magnetic field is responsible for the geometric variations and these changes are identified as topological aspects in graphene. By varying the geometry of the graphene one can create topologically distinct surfaces which could be remarked as torus or sphere.

What are surface states in semiconductor?

Surface states are electronic states found at the surface of materials. They are formed due to the sharp transition from solid material that ends with a surface and are found only at the atom layers closest to the surface….

• Materials science.
• Electronic band structures.
• Semiconductor structures.

What are states in semiconductor?

The electron energy states in a semiconductor form bands, which are large sets of energy states closely spaced in energy. The bands of energy states in a semiconductor are separated by band gaps, which are energy ranges in which there are no electron states.