78 research outputs found
Comment On >Assessment Of Field-Induced Quantum Confinement In Heterogate Germanium Electron-Hole Bilayer Tunnel Field-Effect Transistor> Appl. Phys. Lett. 105, 082108 (2014)
Not AvailableNRI SWAN
programNSF NASCENT ERCMicroelectronics Research CenterElectrical and Computer Engineerin
Density Functional Study of Ternary Topological Insulator Thin Films
Using an ab-initio density functional theory based electronic structure
method with a semi-local density approximation, we study thin-film electronic
properties of two topological insulators based on ternary compounds of Tl
(Thallium) and Bi (Bismuth). We consider TlBiX (X=Se, Te) and Bi_2_2_3$ (X=Se, Te). With this property in combination with
a structurally perfect bulk crystal, the latter ternary compound has been found
to have improved surface electronic transport in recent experiments. In this
article, we discuss the nature of surface states, their locations in the
Brillouin zone and their interactions within the bulk region. Our calculations
suggest a critical thin film thickness to maintain the Dirac cone which is
significantly smaller than that in binary Bi-based compounds. Atomic
relaxations or rearrangements are found to affect the Dirac cone in some of
these compounds. And with the help of layer-projected surface charge densities,
we discuss the penetration depth of the surface states into the bulk region.
The electronic spectrum of these ternary compounds agrees very well with the
available experimental results.Comment: 9 pages, 11 figures, 1 table, Accepted for publication in Physical
Review
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