TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhys.12.2.070
TI  - Assessing the role of interatomic position matrix elements in  tight-binding calculations of optical properties
PY  - 2022/02/22
UR  - https://scipost.org/SciPostPhys.12.2.070
JF  - SciPost Physics
JA  - SciPost Phys.
VL  - 12
IS  - 2
SP  - 070
A1  - Ibanez, Julen
AU  - de Juan, Fernando
AU  - Souza, Ivo
AB  - We study the role of hopping matrix elements of the position operator
$\mathbf{\hat{r}}$ in tight-binding calculations of linear and nonlinear
optical properties of solids. Our analysis relies on a Wannier-interpolation
scheme based on \textit{ab initio} calculations, which automatically includes
matrix elements of $\mathbf{\hat{r}}$ between different Wannier orbitals. A
common approximation, both in empirical tight-binding and in
Wannier-interpolation calculations, is to discard those matrix elements, in
which case the optical response only depends on the on-site energies,
Hamiltonian hoppings, and orbital centers. We find that interatomic
$\mathbf{\hat{r}}$-hopping terms make a sizeable contribution to the shift
photocurrent in monolayer BC$_2$N, a covalent acentric crystal. If a minimal
basis of $p_z$ orbitals on the carbon atoms is used to model the band-edge
response, even the dielectric function becomes strongly dependent on those
terms.
ER  -

@Article{10.21468/SciPostPhys.12.2.070,
	title={{Assessing the role of interatomic position matrix elements in  tight-binding calculations of optical properties}},
	author={Julen Ibañez-Azpiroz and Fernando de Juan and Ivo Souza},
	journal={SciPost Phys.},
	volume={12},
	issue={2},
	pages={70},
	year={2022},
	publisher={SciPost},
	doi={10.21468/SciPostPhys.12.2.070},
	url={https://scipost.org/10.21468/SciPostPhys.12.2.070},
}