Theoretical studies on the effects of pressure, temperature, and aluminum concentration on the optical absorption, refractive index and group velocity within GaAs/Ga1−xAlxAs quantum ring in the presence of Rashba spin–orbit interaction.

The current work focuses on investigating how various external and structural factors can affect the electronic structure and optical properties of a GaAs/Ga1−xAlxAs quantum ring. Specifically, we have studied the effects of spin–orbit interaction (SOI), pressure, temperature, and dimensions on the energy levels, dipole transition matrix elements (DTMEs), susceptibilities, optical absorption coefficients (OACs), refractive index changes (RICs), and group velocity of the quantum ring. These results show that the ground state energy of the system increases with the concentration of aluminum, while increasing temperature and ring size leads to a decrease in DTMEs due to a decrease in wave function overlap. We have also found that the presence of Rashba SOI, pressure, temperature, as well as the ring’s size dominate the electronic structure and subsequently affect the OACs and RICs of the system. A significant enhancement of the OACs can be witnessed when the Rashba coefficient and ring size are enlarged. Furthermore, the results represent a red shift with enhanced Rashba coefficient and relaxation time, whereas the growing ring size results in a blue shift in Optical sensitivities. Finally, we have analyzed the dependence of the group velocity of probe light pulses on the ring's size, photon frequency, and incident optical intensity. Our findings suggest that by controlling these parameters appropriately, it may be possible to achieve effective control of light speed, which could have interesting applications in electro-optical quantum communication networks. Overall, this work sheds light on the potential applications of these findings in the design and construction of spin-based devices and may offer new avenues for further research in this field. [ABSTRACT FROM AUTHOR]