A Fast Method for Estimation of Terahertz Polarization in a Semiconductor Nanodimer

Plasmonic interactions in semiconductor nanoparticles offer the potential of sensors and devices applications in the terahertz frequency range. Charge transport based analysis and simulation of polarization in a semiconductor nanodimer are computationally intensive. A point-dipole decomposition formulation to facilitate time-efficient estimation of the total dipole moment induced by a terahertz electric field on a semiconductor nanodimer is presented. Coupling interactions among the constituent dipoles characterized by their effective local fields provide the basis for a system of algebraic equations from which the total polarization of the dimer can be obtained. Numerical results by this formulation are in very good agreement with that obtained with a finite-element simulation tool applied directly on the nanodimer, with provision to account for space-charge effects.