scholarly journals Band structure and electron-phonon coupling inH3S: A tight-binding model

2016 ◽  
Vol 94 (6) ◽  
Author(s):  
L. Ortenzi ◽  
E. Cappelluti ◽  
L. Pietronero
Keyword(s):  
Band Structure ◽  
Tight Binding ◽  
Tight Binding Model ◽  
Phonon Coupling ◽  
Binding Model ◽  
Electron Phonon Coupling

THEORETICAL ASPECTS OF THE FIELD INDUCED SUPERCONDUCTIVITY IN POLYACENES AND C60

2002 ◽  
Vol 16 (11n12) ◽  
pp. 1547-1551
Author(s):  
S.-L. DRECHSLER ◽  
G. PAASCH ◽  
J. MÁLEK ◽  
S. V. SHULGA ◽  
H. ESCHRIG ◽  
...  
Keyword(s):  
Tight Binding ◽  
Band Structure Calculation ◽  
Full Potential ◽  
Coupling Constant ◽  
Phonon Coupling ◽  
Critical Temperatures ◽  
Binding Model ◽  
Electron Phonon Coupling ◽  
Strong Coulomb ◽  
Experimental Values

The electronic structure and the superconductivity in field-doped polyacenes are considered. Within a modified Thomas–Fermi approach for typical experimental values of the surface charge density the injected charge is confined to a monolayer. The electron–phonon coupling constant for internal modes λintra is estimated using the work of Devos and Lanoo (Ref. 4) and the density of states N(0) estimated from a 2D tight-binding model derived from a full potential LDA band structure calculation for bulk anthracene. The empirical values of the Coulomb pseudopotentials are significantly enhanced. The strong Coulomb interaction is considered as a key quantity which determines the large differences in the critical temperatures achieved for n-doped polyacenes and C 60.

scholarly journals Tight-binding Central Interaction Model for the Band Structure of Silicon

1984 ◽  
Vol 37 (4) ◽  
pp. 407
Author(s):  
GP Betteridge
Keyword(s):  
Band Structure ◽  
Tight Binding ◽  
Interaction Model ◽  
Diamond Lattice ◽  
Nearest Neighbour ◽  
Tight Binding Model ◽  
Binding Model ◽  
Central Interaction

We consider a simple tight-binding model involving all interactions between first and second nearest-neighbour (n.n.) bonds in the diamond lattice. We show that the band structure may be solved analytically in the central approximation in which all second n.n. bond interactions of the same type, for example all bonding: bonding or all bonding: antibonding interactions, are considered equal. The k dependence of the solution is given in terms of the corresponding s-band eigenvalues, which are determined by the topology of the structure.

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 Ab-initio studies of thermal and superconducting properties of HfX2 alloys (X = Tc, Re, and Os)

2014 ◽  
Vol 32 (3) ◽  
pp. 324-330 ◽  
Author(s):  
V. Sathyakumari ◽  
S. Sankar ◽  
K. Mahalakshmi
Keyword(s):  
Band Structure ◽  
Electronic Band Structure ◽  
Tight Binding ◽  
Coupling Constant ◽  
Phonon Coupling ◽  
Electronic Band ◽  
Atomic Sphere ◽  
Electron Phonon Coupling ◽  
Sphere Approximation ◽  
Specific Heat Coefficient

AbstractA systematic study of thermal properties such as the Debye temperature, specific heat coefficient, Grüneisen constant, electron-phonon coupling constant and transition temperature have been carried out using the results of electronic band structure and related characteristics, for hafnium superconducting alloys, namely, HfTc2, HfRe2 and HfOs2. Computation of the electronic band structure and associated properties has been carried out using the tight-binding-linear-muffin-tin-orbital (TBLMTO) method within atomic sphere approximation (ASA). The calculated values have been compared with the available results of literature data.

Sign in / Sign up

Export Citation Format

Share Document