Helical states around a mass-inverted quantum dot in graphene

Topologically protected helical states at a mass-inverted quantum dot in graphene are studied by analyzing both tight-binding and kernel polynomial method calculations. The is introduced considering heterojunction between two different mass domains, which similar to the domain wall bilayer graphene. numerical results show emergent metallic channels across gap when signs of terms opposite. eigenstates revealed be doubly degenerate—each state propagates along opposite directions, maintaining time-reversal symmetry robustness further examined, concluding with fact that secured unless atomic vacancies form near wall. Such circulating topological defects may pave novel route engineering based on