Infrared optical spectra of a silicene quantum dot modulated by spin-orbit coupling and uniaxial strain

Abstract We theoretically study the electronic structure and light absorption spectra of a triangular silicene quantum dot (TZSQD) modulated by spin-orbit coupling (SOC) and the uniaxial strain from a symmetry point of view. After considering the SOC, the symmetry of the system decreases and the degenerate energy level split, creating the absorption peaks in the far-infrared region and some multimodal structures in the near-infrared region and visible region. In addition, the intensity of the SOC also affects the degree of splitting of the energy levels, which makes the absorption peaks in the far-infrared region blueshift to the mid-infrared region, and absorption edge in the near-infrared region redshift to the mid-infrared region. We also find that when a uniaxial strain and SOC coexist at the same time, the symmetry of the system is further reduced and the number of absorption peaks is increased. Moreover, the uniaxial strain intensity can efficiently regulate the frequency position of the absorption edge in the near-infrared region, and make its spectral range greatly expanded.