Spiral dislocation as a tunable geometric parameter for optical responses in quantum rings

Abstract: We investigate the optical and quantum mechanical properties of a charged spinless particle confined in a two-dimensional quantum ring under the simultaneous influence of a spiral dislocation and an external magnetic field. The dislocation is modeled by a torsion-induced metric that alters the spatial geometry without introducing curvature. Using the minimal coupling procedure in curved space, we derive a modified Schr\"odinger equation incorporating both topological and electromagnetic effects. The geometric deformation leads to an energy-dependent effective potential, enabling a tunable control over the bound-state spectrum. We analyze how the spiral dislocation modifies the absorption coefficient, refractive index variation, and photoionization cross-section. The results demonstrate that the dislocation not only shifts the resonance peaks but also enhances or suppresses specific optical transitions depending on the angular momentum. These findings open up possibilities for geometrically tuning light-matter interactions in topological quantum devices.