Electronic confinement of surface states in a topological insulator nanowire

We analyze the confinement of electronic surface states in a model topological insulator nanowire. Spin-momentum locking reduces unwanted backscattering presence nonmagnetic disorder and is known to counteract localization for certain values magnetic flux threading wire. show that intentional can be induced range conditions nanowire constriction. propose geometry involves two constrictions these regions form effective barriers allow formation quantum dot. zero-temperature noninteracting transport through device using Landauer-B\"uttiker approach how externally applied parallel electrostatic gates used control spectrum dot device.