Intra- and interband electron scattering in a hybrid topological insulator: Bismuth bilayer on<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Bi</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Se</mml:mi><mml:mn>3</mml:mn></mml:msub></mml:mrow></mml:math>

Eich, Andreas; Michiardi, Matteo; Bihlmayer, Gustav; Zhu, Xiegang; Mi, Jianli; Iversen, Bo B.; Wiesendanger, R.; Hofmann, Philip; Khajetoorians, Alexander A.; Wiebe, Jens

doi:10.1103/physrevb.90.155414

Cited by 29 publications

(22 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is of particular relevance for strained Bi(111) bilayer islands and substrate-stabilized Bi bilayers [22,23,19,[24][25][26]. To obtain first estimates of how the atomic penetration will be influenced by strain, we perform additional total-energy calculations using single Bi(111) bilayers as a model systems.…”

Section: Resultsmentioning

confidence: 99%

“…It allows for the preparation of nominally undoped systems with metallic and even ferromagnetic electronic states, where backscattering is still suppressed by Rashba splitting. The barrier-free subsorption is not restricted to pure Bi(111) surfaces, but may also be found in the case of Bi(111) bilayer islands and substrate-stabilized Bi bilayers [19,[22][23][24][25][26].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Barrier-free subsurface incorporation of3dmetal atoms into Bi(111) films

et al. 2015

View full text Add to dashboard Cite

By combining scanning tunneling microscopy with density functional theory it is shown that the Bi(111) surface provides a well-defined incorporation site in the first bilayer that traps highly coordinating atoms such as transition metals (TMs) or noble metals. All deposited atoms assume exactly the same specific sevenfold coordinated subsurface interstitial site while the surface topography remains nearly unchanged. Notably, 3d TMs show a barrier-free incorporation. The observed surface modification by barrier-free subsorption helps to suppress aggregation in clusters. It allows a tuning of the electronic properties not only for the pure Bi (111) surface, but may also be observed for topological insulators formed by substrate-stabilized Bi bilayers.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Barrier-free subsurface incorporation of3dmetal atoms into Bi(111) films

et al. 2015

View full text Add to dashboard Cite

show abstract

“…It is independent of the utilized S and t , indicating that this apparent height is most likely topographic in origin. We note that this apparent height is too small to be a Bi bilayer which is typically favorable for Bi growth 36 . In addition to the same moiré structure as on G/Ir, G/Bi/Ir regions show a pronounced line dislocation network, which is absent on G/Ir ( Fig.…”

mentioning

confidence: 99%

Band-gap engineering by Bi intercalation of graphene on Ir(111)

Warmuth¹,

Bruix²,

Michiardi³

et al. 2016

Phys. Rev. B

View full text Add to dashboard Cite

*Correspondence to: a.khajetoorians@science.ru.nlWe report on the structural and electronic properties of a single bismuth layer intercalated underneath a graphene layer grown on an Ir(111) single crystal. Scanning tunneling microscopy (STM) reveals a hexagonal surface structure and a dislocation network upon Bi intercalation, which we attribute to a √3 × √3 R30 ∘ Bi structure on the underlying Ir(111) surface. Ab-initio calculations show that this Bi structure is the most energetically favorable, and also illustrate that STM measurements are most sensitive to C atoms in close proximity to intercalated Bi atoms.Additionally, Bi intercalation induces a band gap ( g = 0.42 eV) at the Dirac point of graphene 2 and an overall n-doping (~0.39 eV), as seen in angular-resolved photoemission spectroscopy.We attribute the emergence of the band gap to the dislocation network which forms favorably along certain parts of the moiré structure induced by the graphene/Ir(111) interface. by the structural confinement in graphene nanoribbons 9 10 ; by the stacking of multiple graphene layers 11,12 ; by the periodic modulation of the graphene lattice (breaking the sub-lattice symmetry), which can be achieved by using patterned substrates 13 , or through the patterned adsorption of other elements such as hydrogen 5 .Pristine graphene shows weak spin-orbit interactions 14 , but increasing the strength of these interactions could give rise to new interesting possibilities in spin-based nanoelectronics. One route toward manipulation of graphene's electronic structure is intercalation of defined The Ir(111) surface was cleaned in ultra-high vacuum (UHV) by repeated cycles of Ar sputtering, followed by annealing to 1470 K. Additionally, carbon contamination was removed, when necessary, by intermittent annealing in O 2 . A monolayer (ML) of high quality graphene was grown by exposing the clean Ir(111) surface to ethylene gas at a surface temperature of 1075 K. The growth process was followed by a short (< 30 ) rapid heating to max = 1455 K.This step increases the quality of the resulting graphene ML. Bismuth was subsequently deposited on the G/Ir(111) surface at a sample temperature of 715 K. After the deposition, the 5 sample was heated to a temperature of 1273 K for 60 s. This step leads to intercalated bismuth underneath the graphene. These surface regions where this intercalation structure is present are referred to as G/Bi/Ir throughout the text.Scanning tunneling microscopy (STM) was performed using a home-built variable temperature STM in a UHV system with a base pressure below 1 × 10 −10 mbar 20 21 . Tip and sample were cooled to = 30 K. Electrochemically etched and flashed W tips were used for all STM measurements. STM topography was recorded in constant current mode ( t ) with the bias applied to the sample ( S ). Differential conductance maps (short I/ V maps) were recorded by applying a modulation voltage ( mod ) using lock-in detection at a modulation frequency of = 5.477 kHz.ARPES data were acquired at the SGM3 beamline at ...

show abstract

“…Previous studies showed that the Bi bilayer grown on TI substrates has Dirac states, becoming metallic [24][25][26][27][28][29][30][31][32][33][34][35]. However, development of the topological Dirac states at such heterostructures is hard to track down due to the complexity of the band structures near the Fermi level, and assignment of the newly emerging Dirac states from Bi bilayers shows inconsistency [26,[31][32][33][34]. A unified concept of the helical states in Bi bilayer-TI heterostructures can provide a key to developing a standard model of mixed-dimensional topological heterostructures.…”

Section: Introductionmentioning

confidence: 99%

Band structure engineering of topological insulator heterojunctions

2016

View full text Add to dashboard Cite

We investigate the topological surface states in heterostructures formed from a three-dimensional topological insulator (TI) and a two-dimensional insulating thin film, using first-principles calculations and the tight-binding method. Utilizing a single Bi or Sb bilayer on top of the topological insulators Bi 2 Se 3 , Bi 2 Te 3 , Bi 2 Te 2 Se, and Sb 2 Te 3 , we find that the surface states evolve in very peculiar but predictable ways. We show that strong hybridization between the bilayer and TI substrates causes the topological surface states to migrate to the top bilayer. It is found that the difference in the work function of constituent layers, which determines the band alignment and the strength of hybridization, governs the character of newly emerged Dirac states.

show abstract

Intra- and interband electron scattering in a hybrid topological insulator: Bismuth bilayer onBi2Se3

Cited by 29 publications

References 47 publications

Barrier-free subsurface incorporation of3dmetal atoms into Bi(111) films

Barrier-free subsurface incorporation of3dmetal atoms into Bi(111) films

Band-gap engineering by Bi intercalation of graphene on Ir(111)

Band structure engineering of topological insulator heterojunctions

Contact Info

Product

Resources

About