Interface phonon-polaritons in quantum well wire systems of polar ternary mixed crystals

• We study interface phonon–polaritons in quantum well wire systems of polar ternary mixed crystals.
• Six polariton modes located in the three forbidden bands of bulk phonon–polaritons.
• Interface phonon–polariton properties depend on the geometric structure and composition of the TMC.
• One or two mode behaviors of interface phonon–polaritons in quantum well wire systems are seen.

The interface phonon–polaritons in quasi-one-dimensional rectangular quantum well wire systems consisting of polar ternary mixed crystals have been investigated with the modified random-element-isodisplacement model and the Born–Huang approximation, combined the Maxwell’s equations and the boundary condition of electromagnetic field. The numerical results of the frequencies of interface phonon–polaritons as functions of the wave-vector, geometric structures, as well as composition x for the quantum well wire systems GaAs/AlxGa1−xAs and ZnxCd1−xSe/ZnSe are gained and discussed. It is shown that there are six branches of interface phonon–polariton modes in quantum well wire systems. The effects of “one mode” and “two mode” behaviors of the ternary mixed crystals on the interface modes are also shown in the dispersion curves.