Tuning Absorption coefficient and refractive index changes in GaAs quantum ring Under Combined Effects of Temperature, Pressure, Rashba and Dresselhaus spin-orbit couplings

Abstract

In the present work, we have explored how the pressure, temperature and size of a GaAs quantum ring in the presence of Rashba and Dresselhaus spin–orbit couplings (SOC) can affect the energy states, dipole transition matrix elements (DTMEs), optical absorption coefficients (OACs) and refractive index changes (RICs). In addition to the theoretical beauty of this important and exciting area of research, it represents the attractive potential applications in the growth of optoelectronics devices. The results have indicated that the ground state energy values rise with pressure and Dresselhaus coupling. Meanwhile, increasing the temperature and Rashba coupling as well as the ring’s size leads to a decrement of energy levels. Taking the transition from the ground state to the first excited state, we have found that the temperature, pressure, inner and outer radius decrease DTMEs because of a drop in wave functions overlap. Therefore, the presence of SOCs, pressure, temperature and dimensions of the quantum ring dominate the electronic behavior and consequently control the absorption as well as the refractive index of the nano structure. A significant enhancement of the OACs and RICs curves is witnessed when the pressure, ring geometric, and Rashba strength are enlarged, but Increasing Dresselhaus coefficient decreases OACs and RICs. These parameters are responsible for blue shifts in the optical absorption. These results can be suitable in the construction of spin-based devices.