Magneto-optics in a Sn doped CdS microcone tuned by quantum confinement effect.

Although magneto-optical phenomena have been studied for decades in low dimensional materials, studying the impact of quantum confinement effects on magneto-optical properties remains a significant challenge. Here, the surface-induced quantum confinement effect in a Sn doped CdS microcone was demonstrated through photoluminescence spectroscopy and angle-resolved photoluminescence spectroscopy. In this structure, the quantum confinement effect has been proven to greatly enhance the tuning range of magneto-optics polarization, and its tuning range nearly 100 %. Through magneto-optical measurement characterization, we attribute ultrabroadband polarization control to the Faraday magneto-optical rotation. Additional first-principles calculations have suggested that the enhancement of the magneto-optical effect is related to isotropic exchange interaction from the hybridization of Sn atoms d-orbitals. Our results highlight the importance of quantum confinement effects in magneto-optical polarizations and motivate novel directions for the manipulation of material properties.