scholarly journals Spin-orbit coupling in anf-electron tight-binding model: Electronic properties of Th, U, and Pu

2009 ◽  
Vol 79 (4) ◽  
Author(s):  
M. D. Jones ◽  
R. C. Albers
Keyword(s):  
Electronic Properties ◽  
Tight Binding ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Tight Binding Model ◽  
Binding Model

SPIN-ORBIT COUPLING IN GRAPHENE UNDER UNIAXIAL STRAIN: TIGHT-BINDING APPROACH AND FIRST-PRINCIPLES CALCULATIONS

2011 ◽  
Vol 25 (11) ◽  
pp. 823-830 ◽  
Author(s):  
BAIHUA GONG ◽  
XIN-HUI ZHANG ◽  
ER-HU ZHANG ◽  
SHENG-LI ZHANG
Keyword(s):  
Band Gap ◽  
First Principles ◽  
Tight Binding ◽  
Uniaxial Strain ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
First Principles Calculations ◽  
Binding Model ◽  
Tight Binding Approximation

Tuning the spin-orbit coupling (SOC) in graphene is highly desired for its application in spintronics. In this paper, we calculated the band gap induced by SOC in graphene under uniaxial strain from a tight-binding model, and found that the band gap has a monotonic increasing dependence on the strain in the range of -20% to 15%. Our results suggest that strain can be used as a reversible and controllable way to tune the SOC in graphene. First-principles calculations were performed, confirming the results of tight-binding approximation.

Quantum anomalous Hall effect on a square lattice with spin–orbit couplings and an exchange field

2014 ◽  
Vol 92 (5) ◽  
pp. 420-424 ◽  
Author(s):  
Xiaoyong Guo ◽  
Xiaobin Ren ◽  
Guangjie Guo ◽  
Jie Peng
Keyword(s):  
Tight Binding ◽  
Chern Number ◽  
Orbit Coupling ◽  
Square Lattice ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Exchange Field ◽  
Edge States ◽  
Binding Model ◽  
Spatial Direction

We investigate a tight-binding model on a two-dimensional square lattice with three terms: the Rashba spin–orbit coupling, the real amplitude next-nearest spin–orbit coupling, and an exchange field. We calculate the first Chern number to identify band topology. It is found that the Chern number takes the quantized values of C1 = 1, 2 and the chiral edge modes can be obtained. Therefore our model realizes the quantum anomalous Hall (QAH) effect. The Rashba coupling is positive for the QAH phase while the next-nearest coupling is detrimental to it. By increasing the exchange field intensity, the Chern number changes from quantized value 2 to 0. The behavior of the edge states is also studied. Particularly for C1 = 2 case, there are two gapless spin-polarized edge states with the same spin polarization moving in the same spatial direction. This indicates that their appearance is topological rather than accidental.

scholarly journals Topological viewpoint of two-dimensional group III-V and IV-IV compounds in the presence of electric field and spin-orbit coupling by density functional theory and tight-binding model

2022 ◽  
Author(s):  
Alireza Baradaran ◽  
Mehdi Ghaffarian
Keyword(s):  
Electric Field ◽  
Density Functional ◽  
Tight Binding ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Binding Model ◽  
Functional Theory ◽  
Group Iii ◽  
Topological Phase Transition

Abstract Using the tight-binding model and density functional theory, the topological invariant of the two-dimensional (2D) group III-V and IV-IV compounds are studied in the absence and the presence of an external perpendicular electric field and spin-orbit coupling. It will be recognized that a critical value of these parameters changes the topological invariant of 2D graphene-like compounds. The significant effects of an external electric field and spin-orbit coupling are considered to the two-center overlap integrals of the Slater-Koster model involved in band structures, changing band-gap, and tuning the topological phase transition between ordinary and quantum spin Hall regime. These declare the good consistency between two theories: tight-binding and density functional. So, this study reveals topological phase transition in these materials. Our finding paves a way to extend an effective Hamiltonian, and may instantly clear some computation aspects of the study in the field of spintronic based on the first-principles methods.

scholarly journals Tight-binding theory of the spin-orbit coupling in graphene

2010 ◽  
Vol 82 (24) ◽  
Author(s):  
Sergej Konschuh ◽  
Martin Gmitra ◽  
Jaroslav Fabian
Keyword(s):  
Tight Binding ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Binding Theory
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