scholarly journals A three-dimensional tight-binding model and magnetic instability of iron selenide KFe2Se2

2012 ◽  
Vol 407 (7) ◽  
pp. 1139-1145 ◽  
Author(s):  
Da-Yong Liu ◽  
Ya-Min Quan ◽  
Zhi Zeng ◽  
Liang-Jian Zou
Keyword(s):  
Tight Binding ◽  
Three Dimensional ◽  
Tight Binding Model ◽  
Binding Model ◽  
Magnetic Instability ◽  
Iron Selenide

scholarly journals Spin fluctuations and superconductivity in a three-dimensional tight-binding model forBaFe2As2

2010 ◽  
Vol 81 (21) ◽  
Author(s):  
S. Graser ◽  
A. F. Kemper ◽  
T. A. Maier ◽  
H.-P. Cheng ◽  
P. J. Hirschfeld ◽  
...  
Keyword(s):  
Tight Binding ◽  
Three Dimensional ◽  
Spin Fluctuations ◽  
Tight Binding Model ◽  
Binding Model

scholarly journals Possible Three-Dimensional Topological Insulator in Pyrochlore Oxides

Symmetry ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1076
Author(s):  
Izumi Hase ◽  
Takashi Yanagisawa
Keyword(s):  
Band Structure ◽  
Topological Insulator ◽  
Nearest Neighbor ◽  
Tight Binding ◽  
Three Dimensional ◽  
Tight Binding Model ◽  
Coupling Constant ◽  
Binding Model ◽  
Effective Spin ◽  
Pyrochlore Oxides

A Kene–Mele-type nearest-neighbor tight-binding model on a pyrochlore lattice is known to be a topological insulator in some parameter region. It is an important task to realize a topological insulator in a real compound, especially in an oxide that is stable in air. In this paper we systematically performed band structure calculations for six pyrochlore oxides A2B2O7 (A = Sn, Pb, Tl; B = Nb, Ta), which are properly described by this model, and found that heavily hole-doped Sn2Nb2O7 is a good candidate. Surprisingly, an effective spin–orbit coupling constant λ changes its sign depending on the composition of the material. Furthermore, we calculated the band structure of three virtual pyrochlore oxides, namely In2Nb2O7, In2Ta2O7 and Sn2Zr2O7. We found that Sn2Zr2O7 has a band gap at the k = 0 (Γ) point, similar to Sn2Nb2O7, though the band structure of Sn2Zr2O7 itself differs from the ideal nearest-neighbor tight-binding model. We propose that the co-doped system (In,Sn)2(Nb,Zr)2O7 may become a candidate of the three-dimensional strong topological insulator.

scholarly journals A three-dimensional tight-binding model for trans-polyacetylene

1991 ◽  
Vol 43 (1-2) ◽  
pp. 3567-3570 ◽  
Author(s):  
X. Wang ◽  
D.K. Campbell ◽  
H.-Q. Lin ◽  
P. Vogl
Keyword(s):  
Tight Binding ◽  
Three Dimensional ◽  
Tight Binding Model ◽  
Binding Model

INCOMMENSURATE CRYSTAL MODEL FOR OPTICAL TRANSMISSION IN Rb2ZnBr4

1987 ◽  
Vol 01 (03) ◽  
pp. 111-114 ◽  
Author(s):  
G. WAHLSTRÖM ◽  
K.A. CHAO
Keyword(s):  
Transmission Spectrum ◽  
Optical Transmission ◽  
Tight Binding ◽  
Three Dimensional ◽  
Optical Transmission Spectrum ◽  
Tight Binding Model ◽  
Binding Model ◽  
Crystal Model

We have calculated the optical transmission spectrum of Rb2ZnBr4 using a three-dimensional tight binding model with modulation along one direction. Our calculation reproduces very well the observed change of spectrum across the normal-to-incommensurate transition at 355 K.

scholarly journals Cobalt-based magnetic Weyl semimetals with high-thermodynamic stabilities

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Wei Luo ◽  
Yuma Nakamura ◽  
Jinseon Park ◽  
Mina Yoon
Keyword(s):  
Tight Binding ◽  
Three Dimensional ◽  
Interlayer Coupling ◽  
First Principles Calculation ◽  
Optimization Approach ◽  
Binding Model ◽  
Nodal Lines ◽  
Weyl Semimetal ◽  
Topological Quantum ◽  
First Time

AbstractRecent experiments identified Co3Sn2S2 as the first magnetic Weyl semimetal (MWSM). Using first-principles calculation with a global optimization approach, we explore the structural stabilities and topological electronic properties of cobalt (Co)-based shandite and alloys, Co3MM’X2 (M/M’ = Ge, Sn, Pb, X = S, Se, Te), and identify stable structures with different Weyl phases. Using a tight-binding model, for the first time, we reveal that the physical origin of the nodal lines of a Co-based shandite structure is the interlayer coupling between Co atoms in different Kagome layers, while the number of Weyl points and their types are mainly governed by the interaction between Co and the metal atoms, Sn, Ge, and Pb. The Co3SnPbS2 alloy exhibits two distinguished topological phases, depending on the relative positions of the Sn and Pb atoms: a three-dimensional quantum anomalous Hall metal, and a MWSM phase with anomalous Hall conductivity (~1290 Ω−1 cm−1) that is larger than that of Co2Sn2S2. Our work reveals the physical mechanism of the origination of Weyl fermions in Co-based shandite structures and proposes topological quantum states with high thermal stability.

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