Self-consistent k . p calculations for gated thin layers of three-dimensional topological insulators

Topological protected surface states are one of the hallmarks of three-dimensional topological insulators. In this paper we theoretically analyze the gate-voltage effects on a quasi-3D layer of HgTe. We find that while the gapless surface states dominate the transport, as an external gate voltage is applied, the existence of bulk charge carriers is likely to occur. We also find that due to screening effects, physical properties that arise from the bottom surface are gate-voltage independent. Finally, we point out the experimental signatures that characterize these effects.