Thermodynamic properties of a Morse-confined GaAs quantum system with a conical disclination under crossed electric and magnetic fields

Abstract This work examines how a conical disclination influences the motion of a particle trapped in a Morse potential. The kink parameter κ characterizes the disclination in the system. A crossed electric and magnetic fields are applied along the radial and the axial directions, respectively. The energy spectrum is obtained by solving the Schrödinger equation within the effective mass approximation using finite difference method (FDM). Based on this, the thermodynamic properties of the system are analyzed using the canonical ensemble framework. The results show that the topological defect and the external fields significantly modify the energy spectrum and remove the degeneracy of the ± m states. In the absence of external fields, the effect of κ on the internal energy (U), heat capacity (c v ), and entropy (S) remains relatively weak over most of the temperature range considered. The application of the magnetic field makes the influence of the defect more pronounced, while the additional radial electric field predominantly controls the thermodynamic response through an overall shift of the energy spectrum. The magnetic susceptibility also shows a clear defect dependent behavior, with the κ = 0.75 case exhibiting a diamagnetic to paramagnetic crossover as the magnetic energy increases.