Gate field effects on the topological insulator BiSbTeSe2 interface
arXiv:1910.06994 · doi:10.1063/1.5127065
Abstract
Interfaces between two topological insulators are of fundamental interest in condensed matter physics. Inspired by experimental efforts, we study interfacial processes between two slabs of BiSbTeSe2 (BSTS) via first principles calculations. Topological surface states are absent for the BSTS interface at its equilibrium separation, but our calculations show that they appear if the inter-slab distance is greater than 6 Ang. More importantly, we find that topological interface states can be preserved by inserting two or more layers of hexagonal boron nitride between the two BSTS slabs. In experiments, the electric current tunneling through the interface is insensitive to back gate voltage when the bias voltage is small. Using a first-principles based method that allows us to simulate gate field, we show that at low bias the extra charge induced by a gate voltage resides on the surface that is closest to the gate electrode, leaving the interface almost undoped. This provides clues to understand the origin of the observed insensitivity of transport properties to back voltage at low bias. Our study resolves a few questions raised in experiment, which does not yet offer a clear correlation between microscopic physics and transport data. We provide a road map for the design of vertical tunneling junctions involving the interface between two topological insulators.
References in corpus (24)
- The SIESTA method for ab initio order-N materials simulation
- Efficient index handling of multidimensional periodic boundary conditions
- Van der Waals Density Functional for General Geometries
- Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
- First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
- The Alloy Theoretic Automated Toolkit: A User Guide
- Efficient implementation of a van der Waals density functional: Application to double-wall carbon nanotubes
- Computing topological invariants without inversion symmetry
- Ab Initio Theory of Gate Induced Gaps in Graphene Bilayers
- Observation of topological surface state quantum Hall effect in an intrinsic three-dimensional topological insulator
- Z2Pack: Numerical Implementation of Hybrid Wannier Centers for Identifying Topological Materials
- Observation of Dirac Holes and Electrons in a Topological Insulator
- Surface State Transport and Ambipolar Electric Field Effect in Bi2Se3 Nanodevices
- Tolerance of topological surface states towards magnetic moments: Fe on Bi2Te3 and Bi2Se3
- Growth of High-Mobility Bi2Te2Se Nanoplatelets on hBN Sheets by van der Waals Epitaxy
- Proximity Driven Enhanced Magnetic Order at Ferromagnetic Insulator / Magnetic Topological Insulator Interface
- Quantum transport of two-species Dirac fermions in dual-gated three-dimensional topological insulators
- Band structure and spin texture of BiSe/3d ferromagnetic metal interface
- Electric field driven quantum phase transition between band insulator and topological insulator
- Single Dirac-cone on the Cs-covered topological insulator surface Sb2Te3(0001)
- Gate-tunable supercurrent and multiple Andreev reflections in a superconductor-topological insulator nanoribbon-superconductor hybrid device
- Band Structure of Topological Insulator BiSbTe1.25Se1.75
- Direct observation of decoupled Dirac states at the interface between topological and normal insulators
- Gate-controlled one-dimensional channel on the topological surface