Growth of bilayer stanene on a magnetic topological insulator aided by a buffer layer

Abstract

Stanene, a two-dimensional counterpart to graphene, has the potential to exhibit novel quantum phenomena when grown on a magnetic topological insulator (MTI). This work demonstrates the formation of up to bilayer stanene on 30\% Sb-doped MnBi${}_2$Te${}_4$ (MBST), a well known MTI, albeit with a buffer layer (BL) in between. Angle-resolved photoemission spectroscopy (ARPES), when combined with density functional theory (DFT), reveals stanene related bands such as two hole-like bands and an inverted parabolic band around the $\overline{\Gamma }$ point. An outer hole-like band traverses the Fermi level (\ef) and gives rise to a hexagonal Fermi surface, showing that stanene on MBST is metallic. In contrast, a bandgap of 0.8 eV is observed at the $\overline{K}$ point. We find that DFT shows good agreement with ARPES only when the BL and hydrogen passivation of the top Sn layer are considered in the calculation. Scanning tunneling microscopy (STM) establishes the honeycomb buckled structure of stanene. A stanene-related component is also detected in the Sn $d$ core level spectra, in addition to a BL-related component. The BL, which forms because of the chemical bonding between Sn and the top two layers of MBST, has an ordered crystal lattice with random anti-site defects. The composition of the BL is estimated to be Sn:Te:Bi/Sb $\approx$ 2:1:1 from x-ray photoelectron spectroscopy. Low energy electron diffraction shows that the lattice constant of stanene is marginally larger than that of MBST, and the STM result aligns with this. The BL bridges this disparity and provides a platform for stanene growth.

*Both authors contributed equally

References in corpus (15)

• Electric Field Effect in Atomically Thin Carbon Films
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Quantized Anomalous Hall Effect in Magnetic Topological Insulators
• Titanic Magnetoresistance in WTe2
• Quantum metric nonlinear Hall effect in a topological antiferromagnetic heterostructure
• Topological Surface States and Dirac point tuning in ternary Bi2Te2Se class of topological insulators
• Enhanced superconducting pairing interaction in indium-doped tin telluride
• Strain-Induced Band Engineering in Monolayer Stanene on Sb(111)
• Crossover of Ising- to Rashba-Type Superconductivity in Epitaxial Bi2Se3/Monolayer NbSe2 Heterostructures
• Dissociative Adsorption of Molecules on Graphene and Silicene
• Electronic structure of Au-Sn compounds grown on Au(111)
• Large Itinerant Electron Exchange Coupling in the Magnetic Topological Insulator MnBi2Te4
• Charge density wave induced nodal lines in LaTe${}_3$
• Giant atomic swirl in graphene bilayers with biaxial heterostrain
• Anti-site defect-induced disorder in compensated topological magnet MnBi${}_{2-x}$Sb${}_x$Te${}_4$

Cited by in corpus (1)

• Geometry-Driven Moiré Engineering in Twisted Bilayers of High-Pseudospin Fermions