Eur. Phys. J. Plus (2021) 136: 555
https://doi.org/10.1140/epjp/s13360-021-01543-4

Regular Article

The nonlinear optical absorption in ${\text{Al}}_x{\text{Ga}}_{1-x}$As/GaAs double-graded quantum wells: magnetic field effect and the position-dependent effective mass effect

¹ School of Physics and Electronics, Yancheng Teachers University, 224002, Yancheng, China
² Department of Physics, College of Physics and Electronic Engineering, Guangzhou University, 510006, Guangzhou, China
³ Laboratoire de la matière condensée et Sciences Interdisciplinaires (LAMCScI), Group of Optoelectronic of Semiconductors and Nanomaterials, ENSET, Mohammed V University in Rabat, Rabat, Morocco
⁴ The Laboratory of Biomedical Photonics and Engineering, Guangxi Medical University, 530021, Nanning, People’s Republic of China

^f jianhui831110@gxmu.edu.com
^g zhangzhihai3344@mail.bnu.edu.cn

Received: 14 March 2021
Accepted: 6 May 2021
Published online: 18 May 2021

Abstract

In this study, the intersubband optical absorption coefficients (OACs) in double-graded quantum wells (QWs) with constant effective mass and position-dependent effective mass (PDEM) are investigated for different applied magnetic field, respectively. The energy levels and the envelope wave functions of an electron confined in finite potential double-graded QWs are calculated by finite difference method. The analytical expressions of the linear, third-order nonlinear and total OACs are obtained using compact density matrix approach. The numerical results show that the applied magnetic field, structure parameters and PDEM have a great effect on the optical characteristics of these structures. In particular, we have found the PDEM have a significant effect on the magnitude position of resonant peaks of OACs.