A quantum magneto-photo-thermoelastic model for wave propagation in laser-excited semiconductors

This study presents a general theoretical framework for analyzing wave propagation in semiconductor media under laser excitation in the presence of an external magnetic field. The proposed formulation extends classical photo-thermoelastic semiconductor models by incorporating quantum-modified carrier transport together with magneto-thermoelastic coupling. Quantum effects are introduced through a density-gradient approach, yielding a higher-order spatial diffusion term that captures nonlocal carrier behavior at micro- and nano-scales. In contrast to multi-temperature formulations, a single-temperature generalized heat conduction model is adopted to provide a clearer representation of thermal-mechanical interactions. The governing equations, which describe the coupling among elastic deformation, the temperature field, and the excess carrier density, are solved using normal-mode analysis to obtain dispersion relations and analytical expressions for the physical fields. Numerical computations are performed for silicon to investigate the influence of magnetic field intensity on temperature, displacement, carrier density, and stress components. The results indicate that the magnetic field induces significant attenuation and phase modification due to Lorentz-force-related damping, while quantum diffusion smooths carrier gradients and enhances spatial distribution. The combined effects lead to improved stability and controlled wave propagation. The developed model provides useful insights for the design of semiconductor devices operating under coupled photothermal and electromagnetic environments.