Effective spin-orbit couplings in an analytical tight-binding model of DNA: Spin filtering and chiral spin transport

2016 ◽  
Vol 93 (15) ◽  
Author(s):  
Solmar Varela ◽  
Vladimiro Mujica ◽  
Ernesto Medina
1993 ◽  
Vol 325 ◽  
Author(s):  
J.H. Xu ◽  
E.G. Wang ◽  
C.S. Ting ◽  
W.P. Su

AbstractThe band structures of three group-V semimetals As, Sb, and Bi with rhombohedral A7 symmetry are studied using a second-neighbor tight-binding model including spin-orbit interaction with an sp3s* basis. Then the bulk tight-binding parameters are used to investigate the electronic properties of semimetal-semiconductor superlattices made of alternating (111) layers of Sb and GaSb or AlSb. It is found that the band gap can be adjustable depending primarily on the thickness of the Sb layers. An interface state is observed in the region of the gap.


2003 ◽  
Vol 02 (06) ◽  
pp. 411-417 ◽  
Author(s):  
M. O. NESTOKLON

A theory of Tamm-like hole states at type II heterointerface has been developed for zink-blende semiconductors. The consideration has been carried out in the microscopic tight-binding model with allowance made for the spin-orbit splitting of the valence band. It has been demonstrated that the tight-binding method describes Tamm-like hole states at type II semiconductor interface. Localization energy dependence on interface tight-binding parameters has been analyzed.


2020 ◽  
Vol 101 (17) ◽  
Author(s):  
Guilhem Manchon ◽  
Sumit Ghosh ◽  
Cyrille Barreteau ◽  
Aurélien Manchon

Symmetry ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1076
Author(s):  
Izumi Hase ◽  
Takashi Yanagisawa

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.


2021 ◽  
Author(s):  
Joy Sharma ◽  
Nishat Mahzabin Helaly ◽  
Mahbub Alam

Abstract In this paper, we have investigated the transport of topological edge states in 2D Zigzag edge Tungsten Ditelluride Nanoribbon (ZTDNR).We have found that zigzag edge nanoribbon (NR) of Tungsten Ditelluride develops topological edge states in the presence of intrinsic spin orbit interaction (SOC). We have used three band tight binding model for the electrons of dz2 , dxy, and dx2 - y2 orbitals with SOC for calculating band structure of NR and Non Equilibrium Greens Function (NEGF) formalism for transport in the NR. We have investigated transport in a pristine device, transport in the presence of a finite potential barrier, transport with constriction within the device and transport with edge imperfections.


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