Solution to the hole-doping problem and tunable quantum Hall effect in Bi${}_2$Se${}_3$ thin films

Abstract

Bi${}_2$Se${}_3$, one of the most widely studied topological insulators (TIs), is naturally electron-doped due to n-type native defects. However, many years of efforts to achieve p-type Bi${}_2$Se${}_3$ thin films have failed so far. Here, we provide a solution to this long-standing problem, showing that the main culprit has been the high density of interfacial defects. By suppressing these defects through an interfacial engineering scheme, we have successfully implemented p-type Bi${}_2$Se${}_3$ thin films down to the thinnest topological regime. On this platform, we present the first tunable quantum Hall effect (QHE) study in Bi${}_2$Se${}_3$ thin films, and reveal not only significantly asymmetric QHE signatures across the Dirac point but also the presence of competing anomalous states near the zeroth Landau level. The availability of doping tunable Bi${}_2$Se${}_3$ thin films will now make it possible to implement various topological quantum devices, previously inaccessible.

40 Pages, 8 Figures, 2 Tables, Accepted to Nano Letters

References in corpus (10)

• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Bulk Band Gap and Surface State Conduction Observed in Voltage-Tuned Crystals of the Topological Insulator Bi${}_2$Se${}_3$
• Quantum Hall Effect on Top and Bottom Surface States of Topological Insulator (Bi1-xSbx)2Te3 Films
• Emergence of decoupled surface transport channels in bulk insulating Bi2Se3 thin films
• Surface versus bulk state in topological insulator Bi2Se3 under environmental disorder
• Restoring Pristine Bi2Se3 Surface with an Effective Se Decapping Process
• Finite-size and composition-driven topological phase transition in (Bi${}_{1-x}$In${}_x$)${}_2$Se${}_3$ thin films
• Surface Shubnikov-de Hass oscillations and non-zero Berry phases of the topological hole conduction in Tl${}_{1-x}$Bi${}_{1+x}$Se${}_2$
• Carrier density dependence of the magnetic properties in iron-doped Bi2Se3 topological insulator
• Disorder-driven topological phase transition in Bi2Se3 films

Cited by in corpus (3)

• Record-High Proximity-Induced Anomalous Hall Effect in (Bi${}_x$Sb${}_{1-x}$)2Te${}_3$ Thin Film Grown on CrGeTe${}_3$ Substrate
• Bulk-Free Topological Insulator Bi2Se3 nanoribbons with Magnetotransport Signatures of Dirac Surface States
• Ferromagnetic Anomalous Hall Effect in Cr-doped Bi${}_2$Se${}_3$ Thin Films via Surface-State Engineering