Strain induced Z{sub 2} topological insulating state of β-As{sub 2}Te{sub 3}
- Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064 (India)
Topological insulators are non-trivial quantum states of matter which exhibit a gap in the electronic structure of their bulk form, but a gapless metallic electronic spectrum at the surface. Here, we predict a uniaxial strain induced electronic topological transition (ETT) from a band to topological insulating state in the rhombohedral phase (space group: R3{sup ¯}m) of As{sub 2}Te{sub 3} (β-As{sub 2}Te{sub 3}) through first-principles calculations including spin-orbit coupling within density functional theory. The ETT in β-As{sub 2}Te{sub 3} is shown to occur at the uniaxial strain ϵ{sub zz} = −0.05 (σ{sub zz} = 1.77 GPa), passing through a Weyl metallic state with a single Dirac cone in its electronic structure at the Γ point. We demonstrate the ETT through band inversion and reversal of parity of the top of the valence and bottom of the conduction bands leading to change in the ℤ{sub 2} topological invariant ν{sub 0} from 0 to 1 across the transition. Based on its electronic structure and phonon dispersion, we propose ultra-thin films of As{sub 2}Te{sub 3} to be promising for use in ultra-thin stress sensors, charge pumps, and thermoelectrics.
- OSTI ID:
- 22317997
- Journal Information:
- Applied Physics Letters, Vol. 105, Issue 6; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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