Polarized far infrared magnetoplasmon reflectivity of doped Cd_xMn_1–xTe semimagnetic semiconductor in the Voigt configuration

Abstract

Calculations of the p-polarized far infrared magnetoplasmon reflectivity of semimagnetic semiconductor Cd x Mn 1-x Te doped ternary alloy in the presence of a magnetic field parallel to the surface of the sample (the Voigt geometry) are used to investigate magnetoplasmon and zone center optical phonon frequencies. It is assumed that the sample is characterized by a dielectric tensor in which the optical phonon contribution and free carriers (plasmon and cyclotron response) are included. The results show that the transverse optical phonon mode is sensitive to the alloy composition, x, and can be used to determine the value of x. The longitudinal optical phonon frequencies are shifted due to phonon-plasmon coupling in doped samples. Also, the influence of composition on the vibrational modes in zinc blende Cd x Mn 1-x Te is described within a modified random element isodisplacement (MREI) approach. By indicating the plasmon and cyclotron frequencies from p-polarized reflectivity spectra and the Voigt permittivity, we calculated the carrier concentration and the effective masses of the carriers. Furthermore, we indicate the frequencies of the phonons at the Г, K, X and L high symmetry points of the Brillouin zone based on a microscopic secondneighbor rigid ion model (RIM).

Electronic, lattice vibration and mechanical properties of CdTe, ZnTe, MnTe, MgTe, HgTe and their ternary alloys

“…For comparison, the available experimental and theoretical data are also reported in table 2. The agreement between our results and the known data for CdTe is better than 12% for ε ∞ , but this is not the case for ω LO and ω TO where the agreement with the results reported by Shayestech et al [38] is of 28% and 38% respectively.…”

The Magneto-Optical Response of Diluted Magnetic Semiconductor CdTe-Cd1-xMnxTe Multi Quantum Wells in the Voigt Configuration

“…4). According to the theoretical MREI calculation the Cd 1−x Mn x Te barrier layer should exhibit two-mode behavior [11]. The p-polarized 45…”

“…For the numerical calculations, the phonon frequencies are calculated using an MREI model [11,16] which we extended for the doped multilayer structure.…”

“…The lattice dynamics of bulk Cd 1−x Mn x Te has been investigated in detail, both experimentally and theoretically in the absence of external magnetic field [10]. In the previous work, we present magneto-optical properties of doped Cd 1−x Mn x Te alloy [11]. However, despite progress in device performance, understanding of optical and structural properties of the doped CdTe-Cd x Mn 1−x Te MQWs is still not satisfactory.…”

“…Calculations have been carried out for the Voigt configuration (the magnetic field parallel to the surface and perpendicular to the direction of the propagation). Also, we calculated the optical phonon frequencies by using a modified random element iso-displacement (MREI) model [11] which we extended for the doped multilayer structure.…”