Designing 3D topological insulators by 2D-Xene (X = Ge, Sn) sheet functionalization in GaGeTe-type structures

First-principles calculations show that strain-induced topological phase transition is auniversalphenomenon in those narrow-gap semiconductors for which the valence band maximum (VBM) and conduction band minimum (CBM) have different parities. The transition originates from the opposite responses of the VBM and CBM, whose magnitudes depend critically on the direction of the applied strain. Our work suggests that strain can play a unique role in tuning the electronic properties of topological insulators for device applications, as well as in the achievement of new topological insulators.

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New family of room temperature quantum spin Hall insulators in two-dimensional germanene films

Journal of Materials Chemistry C ◽

10.1039/c6tc00160b ◽

2016 ◽

Vol 4 (10) ◽

pp. 2088-2094 ◽

Cited By ~ 61

Author(s):

Run-wu Zhang ◽

Wei-xiao Ji ◽

Chang-wen Zhang ◽

Sheng-shi Li ◽

Ping Li ◽

...

Keyword(s):

First Principles ◽

Topological Insulators ◽

Room Temperature ◽

Quantum Spin ◽

Band Gaps ◽

Two Dimensional ◽

First Principles Calculations ◽

New Family ◽

Temperature Applications ◽

Quantum Spin Hall

Based on first-principles calculations, we predict that 2D germanene decorated with ethynyl-derivatives (GeC2X; X = H, F, Cl, Br, I) can be topological insulators with large band-gaps for room-temperature applications.

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Intertwined ferroelectricity and topological state in two-dimensional multilayer

npj Computational Materials ◽

10.1038/s41524-021-00643-0 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Yan Liang ◽

Ning Mao ◽

Ying Dai ◽

Liangzhi Kou ◽

Baibiao Huang ◽

...

Keyword(s):

First Principles ◽

Topological Insulators ◽

Response Speed ◽

First Principles Calculations ◽

Design Guideline ◽

Out Of Plane ◽

Topological States ◽

Topological State ◽

Fundamental Research ◽

Two Parameter

AbstractThe intertwined ferroelectricity and band topology will enable the non-volatile control of the topological states, which is of importance for nanoelectrics with low energy costing and high response speed. Nonetheless, the principle to design such system is unclear and the feasible approach to achieve the coexistence of two parameter orders is absent. Here, we propose a general paradigm to design 2D ferroelectric topological insulators by sliding topological multilayers on the basis of first-principles calculations. Taking trilayer Bi2Te3 as a model system, we show that in the van der Waals multilayer based 2D topological insulators, the in-plane and out-of-plane ferroelectricity can be induced through a specific interlayer sliding, to enable the coexistence of ferroelectric and topological orders. The strong coupling of the order parameters renders the topological states sensitive to polarization flip, realizing non-volatile ferroelectric control of topological properties. The revealed design-guideline and ferroelectric-topological coupling not only are useful for the fundamental research of the coupled ferroelectric and topological physics in 2D lattices, but also enable innovative applications in nanodevices.

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Vibrations in binary and ternary topological insulators: First-principles calculations and Raman spectroscopy measurements

Physical Review B ◽

10.1103/physrevb.86.174304 ◽

2012 ◽

Vol 86 (17) ◽

Cited By ~ 62

Author(s):

V. Chis ◽

I. Yu. Sklyadneva ◽

K. A. Kokh ◽

V. A. Volodin ◽

O. E. Tereshchenko ◽

...

Keyword(s):

Raman Spectroscopy ◽

First Principles ◽

Topological Insulators ◽

First Principles Calculations

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Electronic Structure and X-ray Absorption Spectra of Rutile TiO2 Using First-Principles Calculations

Korean Journal of Metals and Materials ◽

10.3365/kjmm.2014.52.12.1025 ◽

2014 ◽

Vol 52 (12) ◽

pp. 1025-1029

Author(s):

Min-Wook Oh ◽

Tae-Gu Kang ◽

Byungki Ryu ◽

Ji Eun Lee ◽

Sung-Jae Joo ◽

...

Keyword(s):

Electronic Structure ◽

Absorption Spectra ◽

First Principles ◽

First Principles Calculations ◽

Rutile Tio2 ◽

X Ray ◽

X Ray Absorption

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To Bend or Not to Bend, the Dilemma of Multiple Bonds

10.26434/chemrxiv.8066747.v1 ◽

2019 ◽

Author(s):

Michele Pizzocchero ◽

Matteo Bonfanti ◽

Rocco Martinazzo

Keyword(s):

First Principles ◽

2D Materials ◽

Main Group ◽

First Principles Calculations ◽

Group 14 ◽

Multiple Bonds ◽

Main Group Elements ◽

Structural Distortions

The manuscript addresses the issue of the structural distortions occurring at multiple bonds between high main group elements, focusing on group 14. These distortions are known as trans-bending in silenes, disilenes and higher group analogues, and buckling in 2D materials likes silicene and germanene. A simple but correlated \sigma + \pi model is developed and validated with first-principles calculations, and used to explain the different behaviour of second- and higher- row elements.

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