Nanoscale physics

Optical absorption in core-shell quantum antidot under applied co-directed electric and magnetic fields
Holovatsky V.A.1, Chubrei M.V.1
1 Depatment of theoretical physics and computing modelling, Chernivtsi National University after Yuriy Fed’kovych. Kotsyubynsky, 2, Chernivtsi - 58012, Ukraine. 
E-mail: v.holovatsky@chnu.edu.ua, chubrei.maryna@chnu.edu.ua

Multilayers spherical quantum dots (MSQD) have attracted much attention of scientists due to modern technology of their growth and wide range of applications in electronic and optoelectronic devices [1]. One of the most famous MSQD is so-called inverted core-shell QD (core-shell antidot), which consist from core and shell (the core has a wider bandgap than the shell). 
The semiconductor MSQD Al0.3Ga0.7As/GaAs/Al0.3Ga0.7As consisting of core Al0.3Ga0.7As, shell-well GaAs and outer shell Al0.3Ga0.7As is under research. 
In order to investigate the effect of external fields on the electron energy spectrum and wave functions the Schrodinger equation is solved
				(1)
with the Hamiltonian
	(2)
where  is the vector potential, is the electric field potential, is the self-polarization potential, is the confining potential.
In order to solve the equation (1), the wave functions are expanded over the complete set of exact functions obtained without the external fields [2]
			(3)
For the nanosystem Al0.3Ga0.7As/GaAs/Al0.3Ga0.7As, linear , third-order nonlinear  and total optical absorption coefficient are defined by using the matrix diagonalization method in the effective mass approximation.

1.	Vasudevan D., Gaddam R. R., Trinchi A., Cole I. Core-shell quantum dots: properties and applications// J. Alloy. Compd.-2015.-636.-P.395-404.
2.	Holovatsky V., Chubrey M., Voitsekhivska O. Effect of electric field on photoionisation cross-section of impurity in multilayered quantum dot// Superlattices and Microstructures. -2020.- 145.-P.106642.