Thermomagnetic Power in Semiconductor Superlattice

The thermomagnetic power of semiconductor superlattices (SSLs) subjected to combined static electric, perpendicular magnetic, and laser-induced oscillating fields is investigated theoretically within the Boltzmann transport framework under the constant relaxation-time approximation. Closed-form analytical expressions are obtained for the conductivity tensor σ ik , thermoelectric tensor β ik , and thermomagnetic power tensor α i k = σ − 1 β . The results demonstrate a pronounced anisotropic and nonlinear thermomagnetic response arising from miniband transport and photon-assisted processes. Specifically, the longitudinal ( α xx ) and off-diagonal ( α xy ) components exhibit remarkably different temperature dependences, including sign reversal and saturation regimes that are strongly controlled by the miniband width Δ, chemical potential ϱ, equilibrium carrier concentration n 0 , and external field amplitudes ( E 0 , E 1 ) . The presence of the laser field introduces oscillatory modulation through Bessel-function terms, enabling dynamic tuning of both the magnitude and direction of the thermomagnetic power. These findings establish SSLs as highly tunable platforms for thermomagnetic energy conversion and sensing, with potential applications in nanoscale thermoelectric devices and photonic field-controlled transport systems.